diff --git a/CMakeLists.txt b/CMakeLists.txt
index 52cef63c1..fe9118685 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -354,6 +354,7 @@ src/engine/platform/c64.cpp
 src/engine/platform/arcade.cpp
 src/engine/platform/tx81z.cpp
 src/engine/platform/ym2203.cpp
+src/engine/platform/ym2203ext.cpp
 src/engine/platform/ym2608.cpp
 src/engine/platform/ym2610.cpp
 src/engine/platform/ym2610ext.cpp
@@ -444,6 +445,7 @@ src/gui/settings.cpp
 src/gui/songInfo.cpp
 src/gui/songNotes.cpp
 src/gui/stats.cpp
+src/gui/subSongs.cpp
 src/gui/sysConf.cpp
 src/gui/sysEx.cpp
 src/gui/util.cpp
diff --git a/papers/format.md b/papers/format.md
index e6d35e832..c7672c29e 100644
--- a/papers/format.md
+++ b/papers/format.md
@@ -29,6 +29,11 @@ furthermore, an `or reserved` indicates this field is always present, but is res
 
 the format versions are:
 
+- 95: Furnace dev95
+- 94: Furnace dev94
+- 93: Furnace dev93
+- 92: Furnace dev92
+- 91: Furnace dev91
 - 90: Furnace dev90
 - 89: Furnace dev89
 - 88: Furnace dev88
@@ -122,26 +127,26 @@ size | description
 -----|------------------------------------
   4  | "INFO" block ID
   4  | reserved
-  1  | time base
-  1  | speed 1
-  1  | speed 2
-  1  | initial arpeggio time
-  4f | ticks per second
+  1  | time base (of first song)
+  1  | speed 1 (of first song)
+  1  | speed 2 (of first song)
+  1  | initial arpeggio time (of first song)
+  4f | ticks per second (of first song)
      | - 60 is NTSC
      | - 50 is PAL
-  2  | pattern length
+  2  | pattern length (of first song)
      | - the limit is 256.
-  2  | orders length
+  2  | orders length (of first song)
      | - the limit is 256 (>=80) or 127 (<80).
-  1  | highlight A
-  1  | highlight B
+  1  | highlight A (of first song)
+  1  | highlight B (of first song)
   2  | instrument count
      | - the limit is 256.
   2  | wavetable count
      | - the limit is 256.
   2  | sample count
      | - the limit is 256.
-  4  | pattern count
+  4  | pattern count (global)
  32  | list of sound chips
      | - possible soundchips:
      |   - 0x00: end of list
@@ -215,6 +220,7 @@ size | description
      |   - 0xb5: tildearrow Sound Unit - 8 channels
      |   - 0xb6: OPN extended - 9 channels
      |   - 0xb7: PC-98 extended - 19 channels
+     |   - 0xb8: YMZ280B - 8 channels
      |   - 0xde: YM2610B extended - 19 channels
      |   - 0xe0: QSound - 19 channels
      |   - 0xfd: Dummy System - 8 channels
@@ -257,20 +263,20 @@ size | description
  4?? | pointers to wavetables
  4?? | pointers to samples
  4?? | pointers to patterns
- ??? | orders
+ ??? | orders (of first song)
      | - a table of bytes
      | - size=channels*ordLen
      | - read orders then channels
      | - the maximum value of a cell is FF (>=80) or 7F (<80).
- ??? | effect columns
+ ??? | effect columns (of first song)
      | - size=channels
- 1?? | channel hide status
+ 1?? | channel hide status (of first song)
      | - size=channels
- 1?? | channel collapse status
+ 1?? | channel collapse status (of first song)
      | - size=channels
- S?? | channel names
+ S?? | channel names (of first song)
      | - a list of channelCount C strings
- S?? | channel short names
+ S?? | channel short names (of first song)
      | - same as above
  STR | song comment
   4f | master volume, 1.0f=100% (>=59)
@@ -291,6 +297,55 @@ size | description
   1  | pitch macro is linear (>=90) or reserved
   1  | pitch slide speed in full linear pitch mode (>=94) or reserved
  18  | reserved
+ --- | **additional subsongs** (>=95)
+ STR | first subsong name
+ STR | first subsong comment
+  1  | number of additional subsongs
+  3  | reserved
+ 4?? | pointers to subsong data
+```
+
+# subsong
+
+from version 95 onwards, Furnace supports storing multiple songs on a single file.
+the way it's currently done is really weird, but it provides for some backwards compatibility (previous versions will only load the first subsong which is already defined in the `INFO` block).
+
+```
+size | description
+-----|------------------------------------
+  4  | "SONG" block ID
+  4  | reserved
+  1  | time base
+  1  | speed 1
+  1  | speed 2
+  1  | initial arpeggio time
+  4f | ticks per second
+     | - 60 is NTSC
+     | - 50 is PAL
+  2  | pattern length
+     | - the limit is 256.
+  2  | orders length
+     | - the limit is 256.
+  1  | highlight A
+  1  | highlight B
+  4  | reserved
+ STR | subsong name
+ STR | subsong comment
+ ??? | orders
+     | - a table of bytes
+     | - size=channels*ordLen
+     | - read orders then channels
+     | - the maximum value of a cell is FF.
+ ??? | effect columns
+     | - size=channels
+ 1?? | channel hide status
+     | - size=channels
+ 1?? | channel collapse status
+     | - size=channels
+ S?? | channel names
+     | - a list of channelCount C strings
+ S?? | channel short names
+     | - same as above
 ```
 
 # instrument
@@ -743,6 +798,8 @@ size | description
   1  | depth
      | - 0: ZX Spectrum overlay drum (1-bit)
      | - 1: 1-bit NES DPCM (1-bit)
+     | - 2: AICA ADPCM
+     | - 3: YMZ ADPCM
      | - 4: QSound ADPCM
      | - 5: ADPCM-A
      | - 6: ADPCM-B
@@ -769,7 +826,8 @@ size | description
   4  | reserved
   2  | channel
   2  | pattern index
-  4  | reserved
+  2  | subsong (>=95) or reserved
+  2  | reserved
  ??? | pattern data
      | - size: rows*(4+effectColumns*2)*2
      | - read shorts in this order:
diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index d9c23d845..0a6fc7e90 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -139,18 +139,18 @@ void DivEngine::walkSong(int& loopOrder, int& loopRow, int& loopEnd) {
   int nextRow=0;
   int effectVal=0;
   DivPattern* pat[DIV_MAX_CHANS];
-  for (int i=0; i<song.ordersLen; i++) {
+  for (int i=0; i<curSubSong->ordersLen; i++) {
     for (int j=0; j<chans; j++) {
-      pat[j]=song.pat[j].getPattern(song.orders.ord[j][i],false);
+      pat[j]=curPat[j].getPattern(curOrders->ord[j][i],false);
     }
-    for (int j=nextRow; j<song.patLen; j++) {
+    for (int j=nextRow; j<curSubSong->patLen; j++) {
       nextRow=0;
       for (int k=0; k<chans; k++) {
-        for (int l=0; l<song.pat[k].effectCols; l++) {
+        for (int l=0; l<curPat[k].effectCols; l++) {
           effectVal=pat[k]->data[j][5+(l<<1)];
           if (effectVal<0) effectVal=0;
           if (pat[k]->data[j][4+(l<<1)]==0x0d) {
-            if (nextOrder==-1 && (i<song.ordersLen-1 || !song.ignoreJumpAtEnd)) {
+            if (nextOrder==-1 && (i<curSubSong->ordersLen-1 || !song.ignoreJumpAtEnd)) {
               nextOrder=i+1;
               nextRow=effectVal;
             }
@@ -695,6 +695,7 @@ void DivEngine::createNew(const int* description) {
   saveLock.lock();
   song.unload();
   song=DivSong();
+  changeSong(0);
   if (description!=NULL) {
     initSongWithDesc(description);
   }
@@ -716,45 +717,55 @@ void DivEngine::swapChannels(int src, int dest) {
   }
 
   for (int i=0; i<256; i++) {
-    song.orders.ord[dest][i]^=song.orders.ord[src][i];
-    song.orders.ord[src][i]^=song.orders.ord[dest][i];
-    song.orders.ord[dest][i]^=song.orders.ord[src][i];
+    curOrders->ord[dest][i]^=curOrders->ord[src][i];
+    curOrders->ord[src][i]^=curOrders->ord[dest][i];
+    curOrders->ord[dest][i]^=curOrders->ord[src][i];
 
-    DivPattern* prev=song.pat[src].data[i];
-    song.pat[src].data[i]=song.pat[dest].data[i];
-    song.pat[dest].data[i]=prev;
+    DivPattern* prev=curPat[src].data[i];
+    curPat[src].data[i]=curPat[dest].data[i];
+    curPat[dest].data[i]=prev;
   }
 
-  song.pat[src].effectCols^=song.pat[dest].effectCols;
-  song.pat[dest].effectCols^=song.pat[src].effectCols;
-  song.pat[src].effectCols^=song.pat[dest].effectCols;
+  curPat[src].effectCols^=curPat[dest].effectCols;
+  curPat[dest].effectCols^=curPat[src].effectCols;
+  curPat[src].effectCols^=curPat[dest].effectCols;
 
-  String prevChanName=song.chanName[src];
-  String prevChanShortName=song.chanShortName[src];
-  bool prevChanShow=song.chanShow[src];
-  bool prevChanCollapse=song.chanCollapse[src];
+  String prevChanName=curSubSong->chanName[src];
+  String prevChanShortName=curSubSong->chanShortName[src];
+  bool prevChanShow=curSubSong->chanShow[src];
+  bool prevChanCollapse=curSubSong->chanCollapse[src];
 
-  song.chanName[src]=song.chanName[dest];
-  song.chanShortName[src]=song.chanShortName[dest];
-  song.chanShow[src]=song.chanShow[dest];
-  song.chanCollapse[src]=song.chanCollapse[dest];
-  song.chanName[dest]=prevChanName;
-  song.chanShortName[dest]=prevChanShortName;
-  song.chanShow[dest]=prevChanShow;
-  song.chanCollapse[dest]=prevChanCollapse;
+  curSubSong->chanName[src]=curSubSong->chanName[dest];
+  curSubSong->chanShortName[src]=curSubSong->chanShortName[dest];
+  curSubSong->chanShow[src]=curSubSong->chanShow[dest];
+  curSubSong->chanCollapse[src]=curSubSong->chanCollapse[dest];
+  curSubSong->chanName[dest]=prevChanName;
+  curSubSong->chanShortName[dest]=prevChanShortName;
+  curSubSong->chanShow[dest]=prevChanShow;
+  curSubSong->chanCollapse[dest]=prevChanCollapse;
 }
 
 void DivEngine::stompChannel(int ch) {
   logV("stomping channel %d",ch);
   for (int i=0; i<256; i++) {
-    song.orders.ord[ch][i]=0;
+    curOrders->ord[ch][i]=0;
   }
-  song.pat[ch].wipePatterns();
-  song.pat[ch].effectCols=1;
-  song.chanName[ch]="";
-  song.chanShortName[ch]="";
-  song.chanShow[ch]=true;
-  song.chanCollapse[ch]=false;
+  curPat[ch].wipePatterns();
+  curPat[ch].effectCols=1;
+  curSubSong->chanName[ch]="";
+  curSubSong->chanShortName[ch]="";
+  curSubSong->chanShow[ch]=true;
+  curSubSong->chanCollapse[ch]=false;
+}
+
+void DivEngine::changeSong(size_t songIndex) {
+  if (songIndex>=song.subsong.size()) return;
+  curSubSong=song.subsong[songIndex];
+  curPat=song.subsong[songIndex]->pat;
+  curOrders=&song.subsong[songIndex]->orders;
+  curSubSongIndex=songIndex;
+  curOrder=0;
+  curRow=0;
 }
 
 void DivEngine::swapChannelsP(int src, int dest) {
@@ -767,6 +778,41 @@ void DivEngine::swapChannelsP(int src, int dest) {
   BUSY_END;
 }
 
+void DivEngine::changeSongP(size_t index) {
+  if (index>=song.subsong.size()) return;
+  if (index==curSubSongIndex) return;
+  stop();
+  BUSY_BEGIN;
+  saveLock.lock();
+  changeSong(index);
+  saveLock.unlock();
+  BUSY_END;
+}
+
+int DivEngine::addSubSong() {
+  if (song.subsong.size()>=127) return -1;
+  BUSY_BEGIN;
+  saveLock.lock();
+  song.subsong.push_back(new DivSubSong);
+  saveLock.unlock();
+  BUSY_END;
+  return song.subsong.size()-1;
+}
+
+bool DivEngine::removeSubSong(int index) {
+  if (song.subsong.size()<=1) return false;
+  stop();
+  BUSY_BEGIN;
+  saveLock.lock();
+  song.subsong[index]->clearData();
+  delete song.subsong[index];
+  song.subsong.erase(song.subsong.begin()+index);
+  changeSong(0);
+  saveLock.unlock();
+  BUSY_END;
+  return true;
+}
+
 void DivEngine::changeSystem(int index, DivSystem which, bool preserveOrder) {
   int chanCount=chans;
   quitDispatch();
@@ -1321,15 +1367,15 @@ void DivEngine::reset() {
   }
   extValue=0;
   extValuePresent=0;
-  speed1=song.speed1;
-  speed2=song.speed2;
+  speed1=curSubSong->speed1;
+  speed2=curSubSong->speed2;
   firstTick=false;
   nextSpeed=speed1;
   divider=60;
-  if (song.customTempo) {
-    divider=song.hz;
+  if (curSubSong->customTempo) {
+    divider=curSubSong->hz;
   } else {
-    if (song.pal) {
+    if (curSubSong->pal) {
       divider=60;
     } else {
       divider=50;
@@ -1476,6 +1522,10 @@ int DivEngine::getRow() {
   return curRow;
 }
 
+size_t DivEngine::getCurrentSubSong() {
+  return curSubSongIndex;
+}
+
 unsigned char DivEngine::getSpeed1() {
   return speed1;
 }
@@ -1485,9 +1535,9 @@ unsigned char DivEngine::getSpeed2() {
 }
 
 float DivEngine::getHz() {
-  if (song.customTempo) {
-    return song.hz;
-  } else if (song.pal) {
+  if (curSubSong->customTempo) {
+    return curSubSong->hz;
+  } else if (curSubSong->pal) {
     return 60.0;
   } else {
     return 50.0;
@@ -1594,6 +1644,7 @@ void DivEngine::unmuteAll() {
 }
 
 int DivEngine::addInstrument(int refChan) {
+  if (song.ins.size()>=256) return -1;
   BUSY_BEGIN;
   DivInstrument* ins=new DivInstrument;
   int insCount=(int)song.ins.size();
@@ -1624,6 +1675,10 @@ int DivEngine::addInstrument(int refChan) {
 }
 
 int DivEngine::addInstrumentPtr(DivInstrument* which) {
+  if (song.ins.size()>=256) {
+    delete which;
+    return -1;
+  }
   BUSY_BEGIN;
   saveLock.lock();
   song.ins.push_back(which);
@@ -1654,10 +1709,10 @@ void DivEngine::delInstrument(int index) {
     song.insLen=song.ins.size();
     for (int i=0; i<chans; i++) {
       for (int j=0; j<256; j++) {
-        if (song.pat[i].data[j]==NULL) continue;
-        for (int k=0; k<song.patLen; k++) {
-          if (song.pat[i].data[j]->data[k][2]>index) {
-            song.pat[i].data[j]->data[k][2]--;
+        if (curPat[i].data[j]==NULL) continue;
+        for (int k=0; k<curSubSong->patLen; k++) {
+          if (curPat[i].data[j]->data[k][2]>index) {
+            curPat[i].data[j]->data[k][2]--;
           }
         }
       }
@@ -1668,6 +1723,7 @@ void DivEngine::delInstrument(int index) {
 }
 
 int DivEngine::addWave() {
+  if (song.wave.size()>=256) return -1;
   BUSY_BEGIN;
   saveLock.lock();
   DivWavetable* wave=new DivWavetable;
@@ -1680,37 +1736,48 @@ int DivEngine::addWave() {
 }
 
 bool DivEngine::addWaveFromFile(const char* path) {
+  if (song.wave.size()>=256) {
+    lastError="too many wavetables!";
+    return false;
+  }
   FILE* f=ps_fopen(path,"rb");
   if (f==NULL) {
+    lastError=fmt::sprintf("%s",strerror(errno));
     return false;
   }
   unsigned char* buf;
   ssize_t len;
   if (fseek(f,0,SEEK_END)!=0) {
     fclose(f);
+    lastError=fmt::sprintf("could not seek to end: %s",strerror(errno));
     return false;
   }
   len=ftell(f);
   if (len<0) {
     fclose(f);
+    lastError=fmt::sprintf("could not determine file size: %s",strerror(errno));
     return false;
   }
   if (len==(SIZE_MAX>>1)) {
     fclose(f);
+    lastError="file size is invalid!";
     return false;
   }
   if (len==0) {
     fclose(f);
+    lastError="file is empty";
     return false;
   }
   if (fseek(f,0,SEEK_SET)!=0) {
     fclose(f);
+    lastError=fmt::sprintf("could not seek to beginning: %s",strerror(errno));
     return false;
   }
   buf=new unsigned char[len];
   if (fread(buf,1,len,f)!=(size_t)len) {
     logW("did not read entire wavetable file buffer!");
     delete[] buf;
+    lastError=fmt::sprintf("could not read entire file: %s",strerror(errno));
     return false;
   }
   fclose(f);
@@ -1790,6 +1857,7 @@ bool DivEngine::addWaveFromFile(const char* path) {
   } catch (EndOfFileException& e) {
     delete wave;
     delete[] buf;
+    lastError="premature end of file";
     return false;
   }
   
@@ -1816,6 +1884,7 @@ void DivEngine::delWave(int index) {
 }
 
 int DivEngine::addSample() {
+  if (song.sample.size()>=256) return -1;
   BUSY_BEGIN;
   saveLock.lock();
   DivSample* sample=new DivSample;
@@ -1830,6 +1899,10 @@ int DivEngine::addSample() {
 }
 
 int DivEngine::addSampleFromFile(const char* path) {
+  if (song.sample.size()>=256) {
+    lastError="too many samples!";
+    return -1;
+  }
   BUSY_BEGIN;
   warnings="";
 
@@ -2025,18 +2098,18 @@ void DivEngine::delSample(int index) {
 
 void DivEngine::addOrder(bool duplicate, bool where) {
   unsigned char order[DIV_MAX_CHANS];
-  if (song.ordersLen>=0xff) return;
+  if (curSubSong->ordersLen>=0xff) return;
   BUSY_BEGIN_SOFT;
   if (duplicate) {
     for (int i=0; i<DIV_MAX_CHANS; i++) {
-      order[i]=song.orders.ord[i][curOrder];
+      order[i]=curOrders->ord[i][curOrder];
     }
   } else {
     bool used[256];
     for (int i=0; i<chans; i++) {
       memset(used,0,sizeof(bool)*256);
-      for (int j=0; j<song.ordersLen; j++) {
-        used[song.orders.ord[i][j]]=true;
+      for (int j=0; j<curSubSong->ordersLen; j++) {
+        used[curOrders->ord[i][j]]=true;
       }
       order[i]=0xff;
       for (int j=0; j<256; j++) {
@@ -2050,19 +2123,19 @@ void DivEngine::addOrder(bool duplicate, bool where) {
   if (where) { // at the end
     saveLock.lock();
     for (int i=0; i<DIV_MAX_CHANS; i++) {
-      song.orders.ord[i][song.ordersLen]=order[i];
+      curOrders->ord[i][curSubSong->ordersLen]=order[i];
     }
-    song.ordersLen++;
+    curSubSong->ordersLen++;
     saveLock.unlock();
   } else { // after current order
     saveLock.lock();
     for (int i=0; i<DIV_MAX_CHANS; i++) {
-      for (int j=song.ordersLen; j>curOrder; j--) {
-        song.orders.ord[i][j]=song.orders.ord[i][j-1];
+      for (int j=curSubSong->ordersLen; j>curOrder; j--) {
+        curOrders->ord[i][j]=curOrders->ord[i][j-1];
       }
-      song.orders.ord[i][curOrder+1]=order[i];
+      curOrders->ord[i][curOrder+1]=order[i];
     }
-    song.ordersLen++;
+    curSubSong->ordersLen++;
     saveLock.unlock();
     curOrder++;
     if (playing && !freelance) {
@@ -2074,21 +2147,21 @@ void DivEngine::addOrder(bool duplicate, bool where) {
 
 void DivEngine::deepCloneOrder(bool where) {
   unsigned char order[DIV_MAX_CHANS];
-  if (song.ordersLen>=0xff) return;
+  if (curSubSong->ordersLen>=0xff) return;
   warnings="";
   BUSY_BEGIN_SOFT;
   for (int i=0; i<chans; i++) {
     bool didNotFind=true;
     logD("channel %d",i);
-    order[i]=song.orders.ord[i][curOrder];
+    order[i]=curOrders->ord[i][curOrder];
     // find free slot
     for (int j=0; j<256; j++) {
       logD("finding free slot in %d...",j);
-      if (song.pat[i].data[j]==NULL) {
+      if (curPat[i].data[j]==NULL) {
         int origOrd=order[i];
         order[i]=j;
-        DivPattern* oldPat=song.pat[i].getPattern(origOrd,false);
-        DivPattern* pat=song.pat[i].getPattern(j,true);
+        DivPattern* oldPat=curPat[i].getPattern(origOrd,false);
+        DivPattern* pat=curPat[i].getPattern(j,true);
         memcpy(pat->data,oldPat->data,256*32*sizeof(short));
         logD("found at %d",j);
         didNotFind=false;
@@ -2102,19 +2175,19 @@ void DivEngine::deepCloneOrder(bool where) {
   if (where) { // at the end
     saveLock.lock();
     for (int i=0; i<chans; i++) {
-      song.orders.ord[i][song.ordersLen]=order[i];
+      curOrders->ord[i][curSubSong->ordersLen]=order[i];
     }
-    song.ordersLen++;
+    curSubSong->ordersLen++;
     saveLock.unlock();
   } else { // after current order
     saveLock.lock();
     for (int i=0; i<chans; i++) {
-      for (int j=song.ordersLen; j>curOrder; j--) {
-        song.orders.ord[i][j]=song.orders.ord[i][j-1];
+      for (int j=curSubSong->ordersLen; j>curOrder; j--) {
+        curOrders->ord[i][j]=curOrders->ord[i][j-1];
       }
-      song.orders.ord[i][curOrder+1]=order[i];
+      curOrders->ord[i][curOrder+1]=order[i];
     }
-    song.ordersLen++;
+    curSubSong->ordersLen++;
     saveLock.unlock();
     curOrder++;
     if (playing && !freelance) {
@@ -2125,17 +2198,17 @@ void DivEngine::deepCloneOrder(bool where) {
 }
 
 void DivEngine::deleteOrder() {
-  if (song.ordersLen<=1) return;
+  if (curSubSong->ordersLen<=1) return;
   BUSY_BEGIN_SOFT;
   saveLock.lock();
   for (int i=0; i<DIV_MAX_CHANS; i++) {
-    for (int j=curOrder; j<song.ordersLen; j++) {
-      song.orders.ord[i][j]=song.orders.ord[i][j+1];
+    for (int j=curOrder; j<curSubSong->ordersLen; j++) {
+      curOrders->ord[i][j]=curOrders->ord[i][j+1];
     }
   }
-  song.ordersLen--;
+  curSubSong->ordersLen--;
   saveLock.unlock();
-  if (curOrder>=song.ordersLen) curOrder=song.ordersLen-1;
+  if (curOrder>=curSubSong->ordersLen) curOrder=curSubSong->ordersLen-1;
   if (playing && !freelance) {
     playSub(false);
   }
@@ -2150,9 +2223,9 @@ void DivEngine::moveOrderUp() {
   }
   saveLock.lock();
   for (int i=0; i<DIV_MAX_CHANS; i++) {
-    song.orders.ord[i][curOrder]^=song.orders.ord[i][curOrder-1];
-    song.orders.ord[i][curOrder-1]^=song.orders.ord[i][curOrder];
-    song.orders.ord[i][curOrder]^=song.orders.ord[i][curOrder-1];
+    curOrders->ord[i][curOrder]^=curOrders->ord[i][curOrder-1];
+    curOrders->ord[i][curOrder-1]^=curOrders->ord[i][curOrder];
+    curOrders->ord[i][curOrder]^=curOrders->ord[i][curOrder-1];
   }
   saveLock.unlock();
   curOrder--;
@@ -2164,15 +2237,15 @@ void DivEngine::moveOrderUp() {
 
 void DivEngine::moveOrderDown() {
   BUSY_BEGIN_SOFT;
-  if (curOrder>=song.ordersLen-1) {
+  if (curOrder>=curSubSong->ordersLen-1) {
     BUSY_END;
     return;
   }
   saveLock.lock();
   for (int i=0; i<DIV_MAX_CHANS; i++) {
-    song.orders.ord[i][curOrder]^=song.orders.ord[i][curOrder+1];
-    song.orders.ord[i][curOrder+1]^=song.orders.ord[i][curOrder];
-    song.orders.ord[i][curOrder]^=song.orders.ord[i][curOrder+1];
+    curOrders->ord[i][curOrder]^=curOrders->ord[i][curOrder+1];
+    curOrders->ord[i][curOrder+1]^=curOrders->ord[i][curOrder];
+    curOrders->ord[i][curOrder]^=curOrders->ord[i][curOrder+1];
   }
   saveLock.unlock();
   curOrder++;
@@ -2185,12 +2258,12 @@ void DivEngine::moveOrderDown() {
 void DivEngine::exchangeIns(int one, int two) {
   for (int i=0; i<chans; i++) {
     for (int j=0; j<256; j++) {
-      if (song.pat[i].data[j]==NULL) continue;
-      for (int k=0; k<song.patLen; k++) {
-        if (song.pat[i].data[j]->data[k][2]==one) {
-          song.pat[i].data[j]->data[k][2]=two;
-        } else if (song.pat[i].data[j]->data[k][2]==two) {
-          song.pat[i].data[j]->data[k][2]=one;
+      if (curPat[i].data[j]==NULL) continue;
+      for (int k=0; k<curSubSong->patLen; k++) {
+        if (curPat[i].data[j]->data[k][2]==one) {
+          curPat[i].data[j]->data[k][2]=two;
+        } else if (curPat[i].data[j]->data[k][2]==two) {
+          curPat[i].data[j]->data[k][2]=one;
         }
       }
     }
@@ -2394,7 +2467,7 @@ void DivEngine::autoNoteOffAll() {
 void DivEngine::setOrder(unsigned char order) {
   BUSY_BEGIN_SOFT;
   curOrder=order;
-  if (order>=song.ordersLen) curOrder=0;
+  if (order>=curSubSong->ordersLen) curOrder=0;
   if (playing && !freelance) {
     playSub(false);
   }
@@ -2417,15 +2490,15 @@ void DivEngine::setSysFlags(int system, unsigned int flags, bool restart) {
 void DivEngine::setSongRate(float hz, bool pal) {
   BUSY_BEGIN;
   saveLock.lock();
-  song.pal=!pal;
-  song.hz=hz;
+  curSubSong->pal=!pal;
+  curSubSong->hz=hz;
   // what?
-  song.customTempo=true;
+  curSubSong->customTempo=true;
   divider=60;
-  if (song.customTempo) {
-    divider=song.hz;
+  if (curSubSong->customTempo) {
+    divider=curSubSong->hz;
   } else {
-    if (song.pal) {
+    if (curSubSong->pal) {
       divider=60;
     } else {
       divider=50;
@@ -2868,5 +2941,6 @@ bool DivEngine::quit() {
   if (yrw801ROM!=NULL) delete[] yrw801ROM;
   if (tg100ROM!=NULL) delete[] tg100ROM;
   if (mu5ROM!=NULL) delete[] mu5ROM;
+  song.unload();
   return true;
 }
diff --git a/src/engine/engine.h b/src/engine/engine.h
index 60f1c520b..a6e502953 100644
--- a/src/engine/engine.h
+++ b/src/engine/engine.h
@@ -45,8 +45,8 @@
 #define BUSY_BEGIN_SOFT softLocked=true; isBusy.lock();
 #define BUSY_END isBusy.unlock(); softLocked=false;
 
-#define DIV_VERSION "dev94"
-#define DIV_ENGINE_VERSION 94
+#define DIV_VERSION "dev95"
+#define DIV_ENGINE_VERSION 95
 
 // for imports
 #define DIV_VERSION_MOD 0xff01
@@ -304,6 +304,7 @@ class DivEngine {
   bool hasLoadedSomething;
   int softLockCount;
   int subticks, ticks, curRow, curOrder, remainingLoops, nextSpeed;
+  size_t curSubSongIndex;
   double divider;
   int cycles;
   double clockDrift;
@@ -414,8 +415,14 @@ class DivEngine {
   void swapChannels(int src, int dest);
   void stompChannel(int ch);
 
+  // change song (UNSAFE)
+  void changeSong(size_t songIndex);
+
   public:
     DivSong song;
+    DivOrders* curOrders;
+    DivChannelData* curPat;
+    DivSubSong* curSubSong;
     DivInstrument* tempIns;
     DivSystem sysOfChan[DIV_MAX_CHANS];
     int dispatchOfChan[DIV_MAX_CHANS];
@@ -606,6 +613,9 @@ class DivEngine {
     // get current row
     int getRow();
 
+    // get current subsong
+    size_t getCurrentSubSong();
+
     // get speed 1
     unsigned char getSpeed1();
 
@@ -802,6 +812,15 @@ class DivEngine {
     // public swap channels
     void swapChannelsP(int src, int dest);
 
+    // public change song
+    void changeSongP(size_t index);
+
+    // add subsong
+    int addSubSong();
+
+    // remove subsong
+    bool removeSubSong(int index);
+
     // change system
     void changeSystem(int index, DivSystem which, bool preserveOrder=true);
 
@@ -903,6 +922,7 @@ class DivEngine {
       curOrder(0),
       remainingLoops(-1),
       nextSpeed(3),
+      curSubSongIndex(0),
       divider(60),
       cycles(0),
       clockDrift(0),
@@ -938,6 +958,8 @@ class DivEngine {
       metroAmp(0.0f),
       metroVol(1.0f),
       totalProcessed(0),
+      curOrders(NULL),
+      curPat(NULL),
       tempIns(NULL),
       oscBuf{NULL,NULL},
       oscSize(1),
@@ -962,6 +984,8 @@ class DivEngine {
         sysFileMapFur[i]=DIV_SYSTEM_NULL;
         sysFileMapDMF[i]=DIV_SYSTEM_NULL;
       }
+
+      changeSong(0);
     }
 };
 #endif
diff --git a/src/engine/fileOps.cpp b/src/engine/fileOps.cpp
index 99b46319d..c63601a4f 100644
--- a/src/engine/fileOps.cpp
+++ b/src/engine/fileOps.cpp
@@ -184,57 +184,57 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
 
     logI("reading module data...");
     if (ds.version>0x0c) {
-      ds.hilightA=reader.readC();
-      ds.hilightB=reader.readC();
+      ds.subsong[0]->hilightA=reader.readC();
+      ds.subsong[0]->hilightB=reader.readC();
     }
 
-    ds.timeBase=reader.readC();
-    ds.speed1=reader.readC();
-    if (ds.version>0x05) {
-      ds.speed2=reader.readC();
-      ds.pal=reader.readC();
-      ds.hz=(ds.pal)?60:50;
-      ds.customTempo=reader.readC();
+    ds.subsong[0]->timeBase=reader.readC();
+    ds.subsong[0]->speed1=reader.readC();
+    if (ds.version>0x07) {
+      ds.subsong[0]->speed2=reader.readC();
+      ds.subsong[0]->pal=reader.readC();
+      ds.subsong[0]->hz=(ds.subsong[0]->pal)?60:50;
+      ds.subsong[0]->customTempo=reader.readC();
     } else {
-      ds.speed2=ds.speed1;
+      ds.subsong[0]->speed2=ds.subsong[0]->speed1;
     }
     if (ds.version>0x0a) {
       String hz=reader.readString(3);
-      if (ds.customTempo) {
+      if (ds.subsong[0]->customTempo) {
         try {
-          ds.hz=std::stoi(hz);
+          ds.subsong[0]->hz=std::stoi(hz);
         } catch (std::exception& e) {
           logW("invalid custom Hz!");
-          ds.hz=60;
+          ds.subsong[0]->hz=60;
         }
       }
     }
     if (ds.version>0x17) {
-      ds.patLen=reader.readI();
+      ds.subsong[0]->patLen=reader.readI();
     } else {
-      ds.patLen=(unsigned char)reader.readC();
+      ds.subsong[0]->patLen=(unsigned char)reader.readC();
     }
-    ds.ordersLen=(unsigned char)reader.readC();
+    ds.subsong[0]->ordersLen=(unsigned char)reader.readC();
 
-    if (ds.patLen<0) {
+    if (ds.subsong[0]->patLen<0) {
       logE("pattern length is negative!");
       lastError="pattern lengrh is negative!";
       delete[] file;
       return false;
     }
-    if (ds.patLen>256) {
+    if (ds.subsong[0]->patLen>256) {
       logE("pattern length is too large!");
       lastError="pattern length is too large!";
       delete[] file;
       return false;
     }
-    if (ds.ordersLen<0) {
+    if (ds.subsong[0]->ordersLen<0) {
       logE("song length is negative!");
       lastError="song length is negative!";
       delete[] file;
       return false;
     }
-    if (ds.ordersLen>127) {
+    if (ds.subsong[0]->ordersLen>127) {
       logE("song is too long!");
       lastError="song is too long!";
       delete[] file;
@@ -242,54 +242,54 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
     }
 
     if (ds.version<20 && ds.version>3) {
-      ds.arpLen=reader.readC();
+      ds.subsong[0]->arpLen=reader.readC();
     } else {
-      ds.arpLen=1;
+      ds.subsong[0]->arpLen=1;
     }
 
     if (ds.system[0]==DIV_SYSTEM_YMU759) {
-      switch (ds.timeBase) {
+      switch (ds.subsong[0]->timeBase) {
         case 0:
-          ds.hz=248;
+          ds.subsong[0]->hz=248;
           break;
         case 1:
-          ds.hz=200;
+          ds.subsong[0]->hz=200;
           break;
         case 2:
-          ds.hz=100;
+          ds.subsong[0]->hz=100;
           break;
         case 3:
-          ds.hz=50;
+          ds.subsong[0]->hz=50;
           break;
         case 4:
-          ds.hz=25;
+          ds.subsong[0]->hz=25;
           break;
         case 5:
-          ds.hz=20;
+          ds.subsong[0]->hz=20;
           break;
         default:
-          ds.hz=248;
+          ds.subsong[0]->hz=248;
           break;
       }
-      ds.customTempo=true;
-      ds.timeBase=0;
+      ds.subsong[0]->customTempo=true;
+      ds.subsong[0]->timeBase=0;
       addWarning("Yamaha YMU759 emulation is incomplete! please migrate your song to the OPL3 system.");
     }
 
     logV("%x",reader.tell());
 
-    logI("reading pattern matrix (%d * %d = %d)...",ds.ordersLen,getChannelCount(ds.system[0]),ds.ordersLen*getChannelCount(ds.system[0]));
+    logI("reading pattern matrix (%d * %d = %d)...",ds.subsong[0]->ordersLen,getChannelCount(ds.system[0]),ds.subsong[0]->ordersLen*getChannelCount(ds.system[0]));
     for (int i=0; i<getChannelCount(ds.system[0]); i++) {
-      for (int j=0; j<ds.ordersLen; j++) {
-        ds.orders.ord[i][j]=reader.readC();
-        if (ds.orders.ord[i][j]>0x7f) {
-          logE("order at %d, %d out of range! (%d)",i,j,ds.orders.ord[i][j]);
-          lastError=fmt::sprintf("order at %d, %d out of range! (%d)",i,j,ds.orders.ord[i][j]);
+      for (int j=0; j<ds.subsong[0]->ordersLen; j++) {
+        ds.subsong[0]->orders.ord[i][j]=reader.readC();
+        if (ds.subsong[0]->orders.ord[i][j]>0x7f) {
+          logE("order at %d, %d out of range! (%d)",i,j,ds.subsong[0]->orders.ord[i][j]);
+          lastError=fmt::sprintf("order at %d, %d out of range! (%d)",i,j,ds.subsong[0]->orders.ord[i][j]);
           delete[] file;
           return false;
         }
         if (ds.version>0x18) { // 1.1 pattern names
-          ds.pat[i].getPattern(j,true)->name=reader.readString((unsigned char)reader.readC());
+          ds.subsong[0]->pat[i].getPattern(j,true)->name=reader.readString((unsigned char)reader.readC());
         }
       }
       if (ds.version>0x03 && ds.version<0x06 && i<16) {
@@ -637,9 +637,9 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
 
     logV("%x",reader.tell());
 
-    logI("reading patterns (%d channels, %d orders)...",getChannelCount(ds.system[0]),ds.ordersLen);
+    logI("reading patterns (%d channels, %d orders)...",getChannelCount(ds.system[0]),ds.subsong[0]->ordersLen);
     for (int i=0; i<getChannelCount(ds.system[0]); i++) {
-      DivChannelData& chan=ds.pat[i];
+      DivChannelData& chan=ds.subsong[0]->pat[i];
       if (ds.version<0x0a) {
         chan.effectCols=1;
       } else {
@@ -652,10 +652,10 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
         delete[] file;
         return false;
       }
-      for (int j=0; j<ds.ordersLen; j++) {
-        DivPattern* pat=chan.getPattern(ds.orders.ord[i][j],true);
+      for (int j=0; j<ds.subsong[0]->ordersLen; j++) {
+        DivPattern* pat=chan.getPattern(ds.subsong[0]->orders.ord[i][j],true);
         if (ds.version>0x08) { // current pattern format
-          for (int k=0; k<ds.patLen; k++) {
+          for (int k=0; k<ds.subsong[0]->patLen; k++) {
             // note
             pat->data[k][0]=reader.readS();
             // octave
@@ -723,7 +723,7 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
           }
         } else { // historic pattern format
           if (i<16) pat->data[0][2]=historicColIns[i];
-          for (int k=0; k<ds.patLen; k++) {
+          for (int k=0; k<ds.subsong[0]->patLen; k++) {
             // note
             pat->data[k][0]=reader.readC();
             // octave
@@ -788,7 +788,7 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
         pitch=reader.readC();
         vol=reader.readC();
       }
-      if (ds.version<=0x05) {
+      if (ds.version<=0x08) {
         sample->rate=ymuSampleRate*400;
       }
       if (ds.version>0x15) {
@@ -798,15 +798,15 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
           sample->depth=16;
         }
       } else {
-        if (ds.version>0x05) {
+        if (ds.version>0x08) {
           sample->depth=16;
         } else {
           // it appears samples were stored as ADPCM back then
-          sample->depth=6;
+          sample->depth=3;
         }
       }
       if (length>0) {
-        if (ds.version>0x05) {
+        if (ds.version>0x08) {
           if (ds.version<0x0b) {
             data=new short[1+(length/2)];
             reader.read(data,length);
@@ -842,8 +842,7 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
 
           delete[] data;
         } else {
-          // ADPCM?
-          // it appears to be a slightly modified version of ADPCM-B!
+          // YMZ ADPCM
           adpcmData=new unsigned char[length];
           logV("%x",reader.tell());
           reader.read(adpcmData,length);
@@ -854,7 +853,7 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
             logE("%d: error while initializing sample!",i);
           }
 
-          memcpy(sample->dataB,adpcmData,length);
+          memcpy(sample->dataZ,adpcmData,length);
           delete[] adpcmData;
         }
       }
@@ -906,6 +905,7 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
     saveLock.lock();
     song.unload();
     song=ds;
+    changeSong(0);
     recalcChans();
     saveLock.unlock();
     BUSY_END;
@@ -930,13 +930,16 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
   unsigned int insPtr[256];
   unsigned int wavePtr[256];
   unsigned int samplePtr[256];
+  unsigned int subSongPtr[256];
   std::vector<int> patPtr;
+  int numberOfSubSongs=0;
   char magic[5];
   memset(magic,0,5);
   SafeReader reader=SafeReader(file,len);
   warnings="";
   try {
     DivSong ds;
+    DivSubSong* subSong=ds.subsong[0];
 
     if (!reader.seek(16,SEEK_SET)) {
       logE("premature end of file!");
@@ -1046,44 +1049,44 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
     }
     reader.readI();
 
-    ds.timeBase=reader.readC();
-    ds.speed1=reader.readC();
-    ds.speed2=reader.readC();
-    ds.arpLen=reader.readC();
-    ds.hz=reader.readF();
-    ds.pal=(ds.hz>=53);
-    ds.customTempo=true;
+    subSong->timeBase=reader.readC();
+    subSong->speed1=reader.readC();
+    subSong->speed2=reader.readC();
+    subSong->arpLen=reader.readC();
+    subSong->hz=reader.readF();
+    subSong->pal=(subSong->hz>=53);
+    subSong->customTempo=true;
 
-    ds.patLen=reader.readS();
-    ds.ordersLen=reader.readS();
+    subSong->patLen=reader.readS();
+    subSong->ordersLen=reader.readS();
 
-    ds.hilightA=reader.readC();
-    ds.hilightB=reader.readC();
+    subSong->hilightA=reader.readC();
+    subSong->hilightB=reader.readC();
 
     ds.insLen=reader.readS();
     ds.waveLen=reader.readS();
     ds.sampleLen=reader.readS();
     int numberOfPats=reader.readI();
 
-    if (ds.patLen<0) {
+    if (subSong->patLen<0) {
       logE("pattern length is negative!");
       lastError="pattern lengrh is negative!";
       delete[] file;
       return false;
     }
-    if (ds.patLen>256) {
+    if (subSong->patLen>256) {
       logE("pattern length is too large!");
       lastError="pattern length is too large!";
       delete[] file;
       return false;
     }
-    if (ds.ordersLen<0) {
+    if (subSong->ordersLen<0) {
       logE("song length is negative!");
       lastError="song length is negative!";
       delete[] file;
       return false;
     }
-    if (ds.ordersLen>256) {
+    if (subSong->ordersLen>256) {
       logE("song is too long!");
       lastError="song is too long!";
       delete[] file;
@@ -1296,18 +1299,18 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
     reader.read(samplePtr,ds.sampleLen*4);
     for (int i=0; i<numberOfPats; i++) patPtr.push_back(reader.readI());
 
-    logD("reading orders (%d)...",ds.ordersLen);
+    logD("reading orders (%d)...",subSong->ordersLen);
     for (int i=0; i<tchans; i++) {
-      for (int j=0; j<ds.ordersLen; j++) {
-        ds.orders.ord[i][j]=reader.readC();
+      for (int j=0; j<subSong->ordersLen; j++) {
+        subSong->orders.ord[i][j]=reader.readC();
       }
     }
 
     for (int i=0; i<tchans; i++) {
-      ds.pat[i].effectCols=reader.readC();
-      if (ds.pat[i].effectCols<1 || ds.pat[i].effectCols>8) {
-        logE("channel %d has zero or too many effect columns! (%d)",i,ds.pat[i].effectCols);
-        lastError=fmt::sprintf("channel %d has too many effect columns! (%d)",i,ds.pat[i].effectCols);
+      subSong->pat[i].effectCols=reader.readC();
+      if (subSong->pat[i].effectCols<1 || subSong->pat[i].effectCols>8) {
+        logE("channel %d has zero or too many effect columns! (%d)",i,subSong->pat[i].effectCols);
+        lastError=fmt::sprintf("channel %d has too many effect columns! (%d)",i,subSong->pat[i].effectCols);
         delete[] file;
         return false;
       }
@@ -1315,25 +1318,25 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
 
     if (ds.version>=39) {
       for (int i=0; i<tchans; i++) {
-        ds.chanShow[i]=reader.readC();
+        subSong->chanShow[i]=reader.readC();
       }
 
       for (int i=0; i<tchans; i++) {
-        ds.chanCollapse[i]=reader.readC();
+        subSong->chanCollapse[i]=reader.readC();
       }
 
       if (ds.version<92) {
         for (int i=0; i<tchans; i++) {
-          if (ds.chanCollapse[i]>0) ds.chanCollapse[i]=3;
+          if (subSong->chanCollapse[i]>0) subSong->chanCollapse[i]=3;
         }
       }
 
       for (int i=0; i<tchans; i++) {
-        ds.chanName[i]=reader.readString();
+        subSong->chanName[i]=reader.readString();
       }
 
       for (int i=0; i<tchans; i++) {
-        ds.chanShortName[i]=reader.readString();
+        subSong->chanShortName[i]=reader.readString();
       }
 
       ds.notes=reader.readString();
@@ -1406,6 +1409,88 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
       }
     }
 
+    // subsongs
+    if (ds.version>=95) {
+      subSong->name=reader.readString();
+      subSong->notes=reader.readString();
+      numberOfSubSongs=(unsigned char)reader.readC();
+      reader.readC(); // reserved
+      reader.readC();
+      reader.readC();
+      // pointers
+      for (int i=0; i<numberOfSubSongs; i++) {
+        subSongPtr[i]=reader.readI();
+      }
+
+      for (int i=0; i<numberOfSubSongs; i++) {
+        ds.subsong.push_back(new DivSubSong);
+        if (!reader.seek(subSongPtr[i],SEEK_SET)) {
+          logE("couldn't seek to subsong %d!",i+1);
+          lastError=fmt::sprintf("couldn't seek to subsong %d!",i+1);
+          ds.unload();
+          delete[] file;
+          return false;
+        }
+
+        reader.read(magic,4);
+        if (strcmp(magic,"SONG")!=0) {
+          logE("%d: invalid subsong header!",i);
+          lastError="invalid subsong header!";
+          ds.unload();
+          delete[] file;
+          return false;
+        }
+        reader.readI();
+
+        subSong=ds.subsong[i+1];
+        subSong->timeBase=reader.readC();
+        subSong->speed1=reader.readC();
+        subSong->speed2=reader.readC();
+        subSong->arpLen=reader.readC();
+        subSong->hz=reader.readF();
+        subSong->pal=(subSong->hz>=53);
+        subSong->customTempo=true;
+
+        subSong->patLen=reader.readS();
+        subSong->ordersLen=reader.readS();
+
+        subSong->hilightA=reader.readC();
+        subSong->hilightB=reader.readC();
+
+        reader.readI(); // reserved
+
+        subSong->name=reader.readString();
+        subSong->notes=reader.readString();
+
+        logD("reading orders of subsong %d (%d)...",i+1,subSong->ordersLen);
+        for (int j=0; j<tchans; j++) {
+          for (int k=0; k<subSong->ordersLen; k++) {
+            subSong->orders.ord[j][k]=reader.readC();
+          }
+        }
+
+        for (int i=0; i<tchans; i++) {
+          subSong->pat[i].effectCols=reader.readC();
+        }
+
+        for (int i=0; i<tchans; i++) {
+          subSong->chanShow[i]=reader.readC();
+        }
+
+        for (int i=0; i<tchans; i++) {
+          subSong->chanCollapse[i]=reader.readC();
+        }
+
+        for (int i=0; i<tchans; i++) {
+          subSong->chanName[i]=reader.readString();
+        }
+
+        for (int i=0; i<tchans; i++) {
+          subSong->chanShortName[i]=reader.readString();
+        }
+      }
+    }
+
     // read instruments
     for (int i=0; i<ds.insLen; i++) {
       DivInstrument* ins=new DivInstrument;
@@ -1569,9 +1654,15 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
 
       int chan=reader.readS();
       int index=reader.readS();
-      reader.readI();
+      int subs=0;
+      if (ds.version>=95) {
+        subs=reader.readS();
+      } else {
+        reader.readS();
+      }
+      reader.readS();
 
-      logD("- %d, %d",chan,index);
+      logD("- %d, %d, %d",subs,chan,index);
 
       if (chan<0 || chan>=tchans) {
         logE("pattern channel out of range!",i);
@@ -1587,14 +1678,21 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
         delete[] file;
         return false;
       }
+      if (subs<0 || subs>=(int)ds.subsong.size()) {
+        logE("pattern subsong out of range!",i);
+        lastError="pattern subsong out of range!";
+        ds.unload();
+        delete[] file;
+        return false;
+      }
 
-      DivPattern* pat=ds.pat[chan].getPattern(index,true);
-      for (int j=0; j<ds.patLen; j++) {
+      DivPattern* pat=ds.subsong[subs]->pat[chan].getPattern(index,true);
+      for (int j=0; j<ds.subsong[subs]->patLen; j++) {
         pat->data[j][0]=reader.readS();
         pat->data[j][1]=reader.readS();
         pat->data[j][2]=reader.readS();
         pat->data[j][3]=reader.readS();
-        for (int k=0; k<ds.pat[chan].effectCols; k++) {
+        for (int k=0; k<ds.subsong[subs]->pat[chan].effectCols; k++) {
           pat->data[j][4+(k<<1)]=reader.readS();
           pat->data[j][5+(k<<1)]=reader.readS();
         }
@@ -1616,6 +1714,7 @@ bool DivEngine::loadFur(unsigned char* file, size_t len) {
     saveLock.lock();
     song.unload();
     song=ds;
+    changeSong(0);
     recalcChans();
     saveLock.unlock();
     BUSY_END;
@@ -1741,8 +1840,8 @@ bool DivEngine::loadMod(unsigned char* file, size_t len) {
     ds.sampleLen=ds.sample.size();
 
     // orders
-    ds.ordersLen=ordCount=reader.readC();
-    if (ds.ordersLen<1 || ds.ordersLen>127) {
+    ds.subsong[0]->ordersLen=ordCount=reader.readC();
+    if (ds.subsong[0]->ordersLen<1 || ds.subsong[0]->ordersLen>127) {
       logD("invalid order count!");
       throw EndOfFileException(&reader,reader.tell());
     }
@@ -1762,7 +1861,7 @@ bool DivEngine::loadMod(unsigned char* file, size_t len) {
       unsigned char pat=reader.readC();
       if (pat>patMax) patMax=pat;
       for (int j=0; j<chCount; j++) {
-        ds.orders.ord[j][i]=pat;
+        ds.subsong[0]->orders.ord[j][i]=pat;
       }
     }
 
@@ -1779,7 +1878,7 @@ bool DivEngine::loadMod(unsigned char* file, size_t len) {
     }
 
     // patterns
-    ds.patLen=64;
+    ds.subsong[0]->patLen=64;
     for (int ch=0; ch<chCount; ch++) {
       for (int i=0; i<5; i++) {
         fxUsage[ch][i]=false;
@@ -1788,7 +1887,7 @@ bool DivEngine::loadMod(unsigned char* file, size_t len) {
     for (int pat=0; pat<=patMax; pat++) {
       DivPattern* chpats[DIV_MAX_CHANS];
       for (int ch=0; ch<chCount; ch++) {
-        chpats[ch]=ds.pat[ch].getPattern(pat,true);
+        chpats[ch]=ds.subsong[0]->pat[ch].getPattern(pat,true);
       }
       for (int row=0; row<64; row++) {
         for (int ch=0; ch<chCount; ch++) {
@@ -1861,7 +1960,7 @@ bool DivEngine::loadMod(unsigned char* file, size_t len) {
     for (int ch=0; ch<=chCount; ch++) {
       unsigned char fxCols=1;
       for (int pat=0; pat<=patMax; pat++) {
-        auto* data=ds.pat[ch].getPattern(pat,true)->data;
+        auto* data=ds.subsong[0]->pat[ch].getPattern(pat,true)->data;
         short lastPitchEffect=-1;
         short lastEffectState[5]={-1,-1,-1,-1,-1};
         short setEffectState[5]={-1,-1,-1,-1,-1};
@@ -1989,25 +2088,25 @@ bool DivEngine::loadMod(unsigned char* file, size_t len) {
           }
         }
       }
-      ds.pat[ch].effectCols=fxCols;
+      ds.subsong[0]->pat[ch].effectCols=fxCols;
     }
 
-    ds.pal=false;
-    ds.hz=50;
-    ds.customTempo=false;
+    ds.subsong[0]->pal=false;
+    ds.subsong[0]->hz=50;
+    ds.subsong[0]->customTempo=false;
     ds.systemLen=(chCount+3)/4;
     for(int i=0; i<ds.systemLen; i++) {
       ds.system[i]=DIV_SYSTEM_AMIGA;
       ds.systemFlags[i]=1|(80<<8)|(bypassLimits?4:0)|((ds.systemLen>1 || bypassLimits)?2:0); // PAL
     }
     for(int i=0; i<chCount; i++) {
-      ds.chanShow[i]=true;
-      ds.chanName[i]=fmt::sprintf("Channel %d",i+1);
-      ds.chanShortName[i]=fmt::sprintf("C%d",i+1);
+      ds.subsong[0]->chanShow[i]=true;
+      ds.subsong[0]->chanName[i]=fmt::sprintf("Channel %d",i+1);
+      ds.subsong[0]->chanShortName[i]=fmt::sprintf("C%d",i+1);
     }
     for(int i=chCount; i<ds.systemLen*4; i++) {
-      ds.pat[i].effectCols=1;
-      ds.chanShow[i]=false;
+      ds.subsong[0]->pat[i].effectCols=1;
+      ds.subsong[0]->chanShow[i]=false;
     }
     
     // instrument creation
@@ -2025,6 +2124,7 @@ bool DivEngine::loadMod(unsigned char* file, size_t len) {
     saveLock.lock();
     song.unload();
     song=ds;
+    changeSong(0);
     recalcChans();
     saveLock.unlock();
     BUSY_END;
@@ -2119,8 +2219,8 @@ bool DivEngine::loadFTM(unsigned char* file, size_t len) {
           newVibrato=reader.readI();
         }
         if (blockVersion>=4) {
-          ds.hilightA=reader.readI();
-          ds.hilightB=reader.readI();
+          ds.subsong[0]->hilightA=reader.readI();
+          ds.subsong[0]->hilightB=reader.readI();
         }
         if (expansions&8) if (blockVersion>=5) { // N163 channels
           n163Chans=reader.readI();
@@ -2136,12 +2236,12 @@ bool DivEngine::loadFTM(unsigned char* file, size_t len) {
         logV("custom Hz: %d",customHz);
         logV("new vibrato: %d",newVibrato);
         logV("N163 channels: %d",n163Chans);
-        logV("highlight 1: %d",ds.hilightA);
-        logV("highlight 2: %d",ds.hilightB);
+        logV("highlight 1: %d",ds.subsong[0]->hilightA);
+        logV("highlight 2: %d",ds.subsong[0]->hilightB);
         logV("split point: %d",speedSplitPoint);
 
         if (customHz!=0) {
-          ds.hz=customHz;
+          ds.subsong[0]->hz=customHz;
         }
 
         // initialize channels
@@ -2202,7 +2302,7 @@ bool DivEngine::loadFTM(unsigned char* file, size_t len) {
           for (int j=0; j<=totalSongs; j++) {
             unsigned char effectCols=reader.readC();
             if (j==0) {
-              ds.pat[i].effectCols=effectCols+1;
+              ds.subsong[0]->pat[i].effectCols=effectCols+1;
             }
             logV("- song %d has %d effect columns",j,effectCols);
           }
@@ -2533,15 +2633,55 @@ bool DivEngine::load(unsigned char* f, size_t slen) {
   return false;
 }
 
+struct PatToWrite {
+  unsigned short subsong, chan, pat;
+  PatToWrite(unsigned short s, unsigned short c, unsigned short p):
+    subsong(s),
+    chan(c),
+    pat(p) {}
+};
+
 SafeWriter* DivEngine::saveFur(bool notPrimary) {
   saveLock.lock();
-  int insPtr[256];
-  int wavePtr[256];
-  int samplePtr[256];
+  std::vector<int> subSongPtr;
+  std::vector<int> insPtr;
+  std::vector<int> wavePtr;
+  std::vector<int> samplePtr;
   std::vector<int> patPtr;
-  size_t ptrSeek;
+  size_t ptrSeek, subSongPtrSeek;
+  size_t subSongIndex=0;
+  DivSubSong* subSong=song.subsong[subSongIndex];
   warnings="";
 
+  // fail if values are out of range
+  /*
+  if (subSong->ordersLen>256) {
+    logE("maximum song length is 256!");
+    lastError="maximum song length is 256";
+    return NULL;
+  }
+  if (subSong->patLen>256) {
+    logE("maximum pattern length is 256!");
+    lastError="maximum pattern length is 256";
+    return NULL;
+  }
+  */
+  if (song.ins.size()>256) {
+    logE("maximum number of instruments is 256!");
+    lastError="maximum number of instruments is 256";
+    return NULL;
+  }
+  if (song.wave.size()>256) {
+    logE("maximum number of wavetables is 256!");
+    lastError="maximum number of wavetables is 256";
+    return NULL;
+  }
+  if (song.sample.size()>256) {
+    logE("maximum number of samples is 256!");
+    lastError="maximum number of samples is 256";
+    return NULL;
+  }
+
   if (!notPrimary) {
     song.isDMF=false;
     song.version=DIV_ENGINE_VERSION;
@@ -2568,14 +2708,17 @@ SafeWriter* DivEngine::saveFur(bool notPrimary) {
 
   // high short is channel
   // low short is pattern number
-  std::vector<int> patsToWrite;
+  std::vector<PatToWrite> patsToWrite;
   bool alreadyAdded[256];
   for (int i=0; i<chans; i++) {
-    memset(alreadyAdded,0,256*sizeof(bool));
-    for (int j=0; j<song.ordersLen; j++) {
-      if (alreadyAdded[song.orders.ord[i][j]]) continue;
-      patsToWrite.push_back((i<<16)|song.orders.ord[i][j]);
-      alreadyAdded[song.orders.ord[i][j]]=true;
+    for (size_t j=0; j<song.subsong.size(); j++) {
+      DivSubSong* subs=song.subsong[j];
+      memset(alreadyAdded,0,256*sizeof(bool));
+      for (int k=0; k<subs->ordersLen; k++) {
+        if (alreadyAdded[subs->orders.ord[i][k]]) continue;
+        patsToWrite.push_back(PatToWrite(j,i,subs->orders.ord[i][k]));
+        alreadyAdded[subs->orders.ord[i][k]]=true;
+      }
     }
   }
 
@@ -2583,15 +2726,15 @@ SafeWriter* DivEngine::saveFur(bool notPrimary) {
   w->write("INFO",4);
   w->writeI(0);
 
-  w->writeC(song.timeBase);
-  w->writeC(song.speed1);
-  w->writeC(song.speed2);
-  w->writeC(song.arpLen);
-  w->writeF(song.hz);
-  w->writeS(song.patLen);
-  w->writeS(song.ordersLen);
-  w->writeC(song.hilightA);
-  w->writeC(song.hilightB);
+  w->writeC(subSong->timeBase);
+  w->writeC(subSong->speed1);
+  w->writeC(subSong->speed2);
+  w->writeC(subSong->arpLen);
+  w->writeF(subSong->hz);
+  w->writeS(subSong->patLen);
+  w->writeS(subSong->ordersLen);
+  w->writeC(subSong->hilightA);
+  w->writeC(subSong->hilightB);
   w->writeS(song.insLen);
   w->writeS(song.waveLen);
   w->writeS(song.sampleLen);
@@ -2668,29 +2811,29 @@ SafeWriter* DivEngine::saveFur(bool notPrimary) {
   }
 
   for (int i=0; i<chans; i++) {
-    for (int j=0; j<song.ordersLen; j++) {
-      w->writeC(song.orders.ord[i][j]);
+    for (int j=0; j<subSong->ordersLen; j++) {
+      w->writeC(subSong->orders.ord[i][j]);
     }
   }
 
   for (int i=0; i<chans; i++) {
-    w->writeC(song.pat[i].effectCols);
+    w->writeC(subSong->pat[i].effectCols);
   }
 
   for (int i=0; i<chans; i++) {
-    w->writeC(song.chanShow[i]);
+    w->writeC(subSong->chanShow[i]);
   }
 
   for (int i=0; i<chans; i++) {
-    w->writeC(song.chanCollapse[i]);
+    w->writeC(subSong->chanCollapse[i]);
   }
 
   for (int i=0; i<chans; i++) {
-    w->writeString(song.chanName[i],false);
+    w->writeString(subSong->chanName[i],false);
   }
 
   for (int i=0; i<chans; i++) {
-    w->writeString(song.chanShortName[i],false);
+    w->writeString(subSong->chanShortName[i],false);
   }
 
   w->writeString(song.notes,false);
@@ -2715,25 +2858,86 @@ SafeWriter* DivEngine::saveFur(bool notPrimary) {
   for (int i=0; i<18; i++) {
     w->writeC(0);
   }
+  
+  // subsong list
+  w->writeString(subSong->name,false);
+  w->writeString(subSong->notes,false);
+  w->writeC((unsigned char)(song.subsong.size()-1));
+  w->writeC(0); // reserved
+  w->writeC(0);
+  w->writeC(0);
+  subSongPtrSeek=w->tell();
+  // subsong pointers (we'll seek here later)
+  for (size_t i=0; i<(song.subsong.size()-1); i++) {
+    w->writeI(0);
+  }
+
+  /// SUBSONGS
+  for (subSongIndex=1; subSongIndex<song.subsong.size(); subSongIndex++) {
+    subSong=song.subsong[subSongIndex];
+    subSongPtr.push_back(w->tell());
+    w->write("SONG",4);
+    w->writeI(0);
+
+    w->writeC(subSong->timeBase);
+    w->writeC(subSong->speed1);
+    w->writeC(subSong->speed2);
+    w->writeC(subSong->arpLen);
+    w->writeF(subSong->hz);
+    w->writeS(subSong->patLen);
+    w->writeS(subSong->ordersLen);
+    w->writeC(subSong->hilightA);
+    w->writeC(subSong->hilightB);
+    w->writeI(0); // reserved
+
+    w->writeString(subSong->name,false);
+    w->writeString(subSong->notes,false);
+
+    for (int i=0; i<chans; i++) {
+      for (int j=0; j<subSong->ordersLen; j++) {
+        w->writeC(subSong->orders.ord[i][j]);
+      }
+    }
+
+    for (int i=0; i<chans; i++) {
+      w->writeC(subSong->pat[i].effectCols);
+    }
+
+    for (int i=0; i<chans; i++) {
+      w->writeC(subSong->chanShow[i]);
+    }
+
+    for (int i=0; i<chans; i++) {
+      w->writeC(subSong->chanCollapse[i]);
+    }
+
+    for (int i=0; i<chans; i++) {
+      w->writeString(subSong->chanName[i],false);
+    }
+
+    for (int i=0; i<chans; i++) {
+      w->writeString(subSong->chanShortName[i],false);
+    }
+  }
 
   /// INSTRUMENT
   for (int i=0; i<song.insLen; i++) {
     DivInstrument* ins=song.ins[i];
-    insPtr[i]=w->tell();
+    insPtr.push_back(w->tell());
     ins->putInsData(w);
   }
 
   /// WAVETABLE
   for (int i=0; i<song.waveLen; i++) {
     DivWavetable* wave=song.wave[i];
-    wavePtr[i]=w->tell();
+    wavePtr.push_back(w->tell());
     wave->putWaveData(w);
   }
 
   /// SAMPLE
   for (int i=0; i<song.sampleLen; i++) {
     DivSample* sample=song.sample[i];
-    samplePtr[i]=w->tell();
+    samplePtr.push_back(w->tell());
     w->write("SMPL",4);
     w->writeI(0);
 
@@ -2750,23 +2954,24 @@ SafeWriter* DivEngine::saveFur(bool notPrimary) {
   }
 
   /// PATTERN
-  for (int i: patsToWrite) {
-    DivPattern* pat=song.pat[i>>16].getPattern(i&0xffff,false);
+  for (PatToWrite& i: patsToWrite) {
+    DivPattern* pat=song.subsong[i.subsong]->pat[i.chan].getPattern(i.pat,false);
     patPtr.push_back(w->tell());
     w->write("PATR",4);
     w->writeI(0);
 
-    w->writeS(i>>16);
-    w->writeS(i&0xffff);
+    w->writeS(i.chan);
+    w->writeS(i.pat);
+    w->writeS(i.subsong);
 
-    w->writeI(0); // reserved
+    w->writeS(0); // reserved
 
-    for (int j=0; j<song.patLen; j++) {
+    for (int j=0; j<song.subsong[i.subsong]->patLen; j++) {
       w->writeS(pat->data[j][0]); // note
       w->writeS(pat->data[j][1]); // octave
       w->writeS(pat->data[j][2]); // instrument
       w->writeS(pat->data[j][3]); // volume
-      w->write(&pat->data[j][4],2*song.pat[i>>16].effectCols*2); // effects
+      w->write(&pat->data[j][4],2*song.subsong[i.subsong]->pat[i.chan].effectCols*2); // effects
     }
 
     w->writeString(pat->name,false);
@@ -2779,21 +2984,29 @@ SafeWriter* DivEngine::saveFur(bool notPrimary) {
     w->writeI(insPtr[i]);
   }
 
-  // wavetable pointers (we'll seek here later)
+  // wavetable pointers
   for (int i=0; i<song.waveLen; i++) {
     w->writeI(wavePtr[i]);
   }
 
-  // sample pointers (we'll seek here later)
+  // sample pointers
   for (int i=0; i<song.sampleLen; i++) {
     w->writeI(samplePtr[i]);
   }
 
-  // pattern pointers (we'll seek here later)
+  // pattern pointers
   for (int i: patPtr) {
     w->writeI(i);
   }
 
+  /// SUBSONG POINTERS
+  w->seek(subSongPtrSeek,SEEK_SET);
+
+  // subsong pointers
+  for (size_t i=0; i<(song.subsong.size()-1); i++) {
+    w->writeI(subSongPtr[i]);
+  }
+
   saveLock.unlock();
   return w;
 }
@@ -2864,7 +3077,7 @@ SafeWriter* DivEngine::saveDMF(unsigned char version) {
     return NULL;
   }
   // fail if values are out of range
-  if (song.ordersLen>127) {
+  if (curSubSong->ordersLen>127) {
     logE("maximum .dmf song length is 127!");
     lastError="maximum .dmf song length is 127";
     return NULL;
@@ -2880,10 +3093,10 @@ SafeWriter* DivEngine::saveDMF(unsigned char version) {
     return NULL;
   }
   for (int i=0; i<chans; i++) {
-    for (int j=0; j<song.ordersLen; j++) {
-      if (song.orders.ord[i][j]>0x7f) {
-        logE("order %d, %d is out of range (0-127)!",song.orders.ord[i][j]);
-        lastError=fmt::sprintf("order %d, %d is out of range (0-127)",song.orders.ord[i][j]);
+    for (int j=0; j<curSubSong->ordersLen; j++) {
+      if (curOrders->ord[i][j]>0x7f) {
+        logE("order %d, %d is out of range (0-127)!",curOrders->ord[i][j]);
+        lastError=fmt::sprintf("order %d, %d is out of range (0-127)",curOrders->ord[i][j]);
         return NULL;
       }
     }
@@ -2926,31 +3139,35 @@ SafeWriter* DivEngine::saveDMF(unsigned char version) {
   // song info
   w->writeString(song.name,true);
   w->writeString(song.author,true);
-  w->writeC(song.hilightA);
-  w->writeC(song.hilightB);
+  w->writeC(curSubSong->hilightA);
+  w->writeC(curSubSong->hilightB);
   
-  w->writeC(song.timeBase);
-  w->writeC(song.speed1);
-  w->writeC(song.speed2);
-  w->writeC(song.pal);
-  w->writeC(song.customTempo);
+  w->writeC(curSubSong->timeBase);
+  w->writeC(curSubSong->speed1);
+  w->writeC(curSubSong->speed2);
+  w->writeC(curSubSong->pal);
+  w->writeC(curSubSong->customTempo);
   char customHz[4];
   memset(customHz,0,4);
-  snprintf(customHz,4,"%d",(int)song.hz);
+  snprintf(customHz,4,"%d",(int)curSubSong->hz);
   w->write(customHz,3);
-  w->writeI(song.patLen);
-  w->writeC(song.ordersLen);
+  w->writeI(curSubSong->patLen);
+  w->writeC(curSubSong->ordersLen);
 
   for (int i=0; i<chans; i++) {
-    for (int j=0; j<song.ordersLen; j++) {
-      w->writeC(song.orders.ord[i][j]);
+    for (int j=0; j<curSubSong->ordersLen; j++) {
+      w->writeC(curOrders->ord[i][j]);
       if (version>=25) {
-        DivPattern* pat=song.pat[i].getPattern(j,false);
+        DivPattern* pat=curPat[i].getPattern(j,false);
         w->writeString(pat->name,true);
       }
     }
   }
 
+  if (song.subsong.size()>1) {
+    addWarning("only the currently selected subsong will be saved");
+  }
+
   if (sys==DIV_SYSTEM_C64_6581 || sys==DIV_SYSTEM_C64_8580) {
     addWarning("absolute duty/cutoff macro not available in .dmf!");
     addWarning("duty precision will be lost");
@@ -3112,15 +3329,15 @@ SafeWriter* DivEngine::saveDMF(unsigned char version) {
   }
 
   for (int i=0; i<getChannelCount(sys); i++) {
-    w->writeC(song.pat[i].effectCols);
+    w->writeC(curPat[i].effectCols);
 
-    for (int j=0; j<song.ordersLen; j++) {
-      DivPattern* pat=song.pat[i].getPattern(song.orders.ord[i][j],false);
-      for (int k=0; k<song.patLen; k++) {
+    for (int j=0; j<curSubSong->ordersLen; j++) {
+      DivPattern* pat=curPat[i].getPattern(curOrders->ord[i][j],false);
+      for (int k=0; k<curSubSong->patLen; k++) {
         w->writeS(pat->data[k][0]); // note
         w->writeS(pat->data[k][1]); // octave
         w->writeS(pat->data[k][3]); // volume
-        w->write(&pat->data[k][4],2*song.pat[i].effectCols*2); // effects
+        w->write(&pat->data[k][4],2*curPat[i].effectCols*2); // effects
         w->writeS(pat->data[k][2]); // instrument
       }
     }
diff --git a/src/engine/pattern.cpp b/src/engine/pattern.cpp
index 4f4663cae..0a561376b 100644
--- a/src/engine/pattern.cpp
+++ b/src/engine/pattern.cpp
@@ -49,7 +49,7 @@ void DivChannelData::wipePatterns() {
   }
 }
 
-void DivPattern::copyOn(DivPattern *dest) {
+void DivPattern::copyOn(DivPattern* dest) {
   dest->name=name;
   memcpy(dest->data,data,sizeof(data));
 }
diff --git a/src/engine/platform/ym2203ext.cpp b/src/engine/platform/ym2203ext.cpp
index 440dce6a0..7948d51e7 100644
--- a/src/engine/platform/ym2203ext.cpp
+++ b/src/engine/platform/ym2203ext.cpp
@@ -17,20 +17,20 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-#include "ym2610bext.h"
+#include "ym2203ext.h"
 #include "../engine.h"
 #include <math.h>
 
 #include "ym2610shared.h"
 #include "fmshared_OPN.h"
 
-int DivPlatformYM2610BExt::dispatch(DivCommand c) {
+int DivPlatformYM2203Ext::dispatch(DivCommand c) {
   if (c.chan<2) {
-    return DivPlatformYM2610B::dispatch(c);
+    return DivPlatformYM2203::dispatch(c);
   }
   if (c.chan>5) {
     c.chan-=3;
-    return DivPlatformYM2610B::dispatch(c);
+    return DivPlatformYM2203::dispatch(c);
   }
   int ch=c.chan-2;
   int ordch=orderedOps[ch];
@@ -384,7 +384,7 @@ static int opChanOffsH[4]={
   0xad, 0xae, 0xac, 0xa6
 };
 
-void DivPlatformYM2610BExt::tick(bool sysTick) {
+void DivPlatformYM2203Ext::tick(bool sysTick) {
   if (extMode) {
     bool writeSomething=false;
     unsigned char writeMask=2;
@@ -401,7 +401,7 @@ void DivPlatformYM2610BExt::tick(bool sysTick) {
     }
   }
 
-  DivPlatformYM2610B::tick(sysTick);
+  DivPlatformYM2203::tick(sysTick);
 
   bool writeNoteOn=false;
   unsigned char writeMask=2;
@@ -438,13 +438,13 @@ void DivPlatformYM2610BExt::tick(bool sysTick) {
   }
 }
 
-void DivPlatformYM2610BExt::muteChannel(int ch, bool mute) {
+void DivPlatformYM2203Ext::muteChannel(int ch, bool mute) {
   if (ch<2) {
-    DivPlatformYM2610B::muteChannel(ch,mute);
+    DivPlatformYM2203::muteChannel(ch,mute);
     return;
   }
   if (ch>5) {
-    DivPlatformYM2610B::muteChannel(ch-3,mute);
+    DivPlatformYM2203::muteChannel(ch-3,mute);
     return;
   }
   isOpMuted[ch-2]=mute;
@@ -462,7 +462,7 @@ void DivPlatformYM2610BExt::muteChannel(int ch, bool mute) {
   }
 }
 
-void DivPlatformYM2610BExt::forceIns() {
+void DivPlatformYM2203Ext::forceIns() {
   for (int i=0; i<6; i++) {
     for (int j=0; j<4; j++) {
       unsigned short baseAddr=chanOffs[i]|opOffs[j];
@@ -494,7 +494,6 @@ void DivPlatformYM2610BExt::forceIns() {
       rWrite(baseAddr+ADDR_SSG,op.ssgEnv&15);
     }
     rWrite(chanOffs[i]+ADDR_FB_ALG,(chan[i].state.alg&7)|(chan[i].state.fb<<3));
-    rWrite(chanOffs[i]+ADDR_LRAF,(isMuted[i]?0:(chan[i].pan<<6))|(chan[i].state.fms&7)|((chan[i].state.ams&3)<<4));
     if (chan[i].active) {
       chan[i].keyOn=true;
       chan[i].freqChanged=true;
@@ -518,23 +517,23 @@ void DivPlatformYM2610BExt::forceIns() {
   }
 }
 
-void* DivPlatformYM2610BExt::getChanState(int ch) {
+void* DivPlatformYM2203Ext::getChanState(int ch) {
   if (ch>=6) return &chan[ch-3];
   if (ch>=2) return &opChan[ch-2];
   return &chan[ch];
 }
 
-DivDispatchOscBuffer* DivPlatformYM2610BExt::getOscBuffer(int ch) {
+DivDispatchOscBuffer* DivPlatformYM2203Ext::getOscBuffer(int ch) {
   if (ch>=6) return oscBuf[ch-3];
   if (ch<3) return oscBuf[ch];
   return NULL;
 }
 
-void DivPlatformYM2610BExt::reset() {
-  DivPlatformYM2610B::reset();
+void DivPlatformYM2203Ext::reset() {
+  DivPlatformYM2203::reset();
 
   for (int i=0; i<4; i++) {
-    opChan[i]=DivPlatformYM2610BExt::OpChannel();
+    opChan[i]=DivPlatformYM2203Ext::OpChannel();
     opChan[i].vol=127;
   }
 
@@ -543,12 +542,12 @@ void DivPlatformYM2610BExt::reset() {
   extMode=true;
 }
 
-bool DivPlatformYM2610BExt::keyOffAffectsArp(int ch) {
+bool DivPlatformYM2203Ext::keyOffAffectsArp(int ch) {
   return (ch>8);
 }
 
-void DivPlatformYM2610BExt::notifyInsChange(int ins) {
-  DivPlatformYM2610B::notifyInsChange(ins);
+void DivPlatformYM2203Ext::notifyInsChange(int ins) {
+  DivPlatformYM2203::notifyInsChange(ins);
   for (int i=0; i<4; i++) {
     if (opChan[i].ins==ins) {
       opChan[i].insChanged=true;
@@ -556,8 +555,8 @@ void DivPlatformYM2610BExt::notifyInsChange(int ins) {
   }
 }
 
-int DivPlatformYM2610BExt::init(DivEngine* parent, int channels, int sugRate, unsigned int flags) {
-  DivPlatformYM2610B::init(parent,channels,sugRate,flags);
+int DivPlatformYM2203Ext::init(DivEngine* parent, int channels, int sugRate, unsigned int flags) {
+  DivPlatformYM2203::init(parent,channels,sugRate,flags);
   for (int i=0; i<4; i++) {
     isOpMuted[i]=false;
   }
@@ -566,9 +565,9 @@ int DivPlatformYM2610BExt::init(DivEngine* parent, int channels, int sugRate, un
   return 19;
 }
 
-void DivPlatformYM2610BExt::quit() {
-  DivPlatformYM2610B::quit();
+void DivPlatformYM2203Ext::quit() {
+  DivPlatformYM2203::quit();
 }
 
-DivPlatformYM2610BExt::~DivPlatformYM2610BExt() {
+DivPlatformYM2203Ext::~DivPlatformYM2203Ext() {
 }
diff --git a/src/engine/platform/ym2203ext.h b/src/engine/platform/ym2203ext.h
index 4e3f7c5ff..7dde3abb4 100644
--- a/src/engine/platform/ym2203ext.h
+++ b/src/engine/platform/ym2203ext.h
@@ -19,9 +19,9 @@
 
 #include "../dispatch.h"
 
-#include "ym2610b.h"
+#include "ym2203.h"
 
-class DivPlatformYM2610BExt: public DivPlatformYM2610B {
+class DivPlatformYM2203Ext: public DivPlatformYM2203 {
   struct OpChannel {
     DivMacroInt std;
     unsigned char freqH, freqL;
@@ -47,5 +47,5 @@ class DivPlatformYM2610BExt: public DivPlatformYM2610B {
     void notifyInsChange(int ins);
     int init(DivEngine* parent, int channels, int sugRate, unsigned int flags);
     void quit();
-    ~DivPlatformYM2610BExt();
+    ~DivPlatformYM2203Ext();
 };
diff --git a/src/engine/playback.cpp b/src/engine/playback.cpp
index 6a27dc65e..7a2356a7e 100644
--- a/src/engine/playback.cpp
+++ b/src/engine/playback.cpp
@@ -30,7 +30,7 @@ constexpr int MASTER_CLOCK_PREC=(sizeof(void*)==8)?8:0;
 void DivEngine::nextOrder() {
   curRow=0;
   if (repeatPattern) return;
-  if (++curOrder>=song.ordersLen) {
+  if (++curOrder>=curSubSong->ordersLen) {
     endOfSong=true;
     curOrder=0;
   }
@@ -266,11 +266,11 @@ bool DivEngine::perSystemPostEffect(int ch, unsigned char effect, unsigned char
 void DivEngine::processRow(int i, bool afterDelay) {
   int whatOrder=afterDelay?chan[i].delayOrder:curOrder;
   int whatRow=afterDelay?chan[i].delayRow:curRow;
-  DivPattern* pat=song.pat[i].getPattern(song.orders.ord[i][whatOrder],false);
+  DivPattern* pat=curPat[i].getPattern(curOrders->ord[i][whatOrder],false);
   // pre effects
   if (!afterDelay) {
     bool returnAfterPre=false;
-    for (int j=0; j<song.pat[i].effectCols; j++) {
+    for (int j=0; j<curPat[i].effectCols; j++) {
       short effect=pat->data[whatRow][4+(j<<1)];
       short effectVal=pat->data[whatRow][5+(j<<1)];
 
@@ -290,7 +290,7 @@ void DivEngine::processRow(int i, bool afterDelay) {
           }
           break;
         case 0x0d: // next order
-          if (changeOrd<0 && (curOrder<(song.ordersLen-1) || !song.ignoreJumpAtEnd)) {
+          if (changeOrd<0 && (curOrder<(curSubSong->ordersLen-1) || !song.ignoreJumpAtEnd)) {
             changeOrd=-2;
             changePos=effectVal;
           }
@@ -405,7 +405,7 @@ void DivEngine::processRow(int i, bool afterDelay) {
   bool panChanged=false;
 
   // effects
-  for (int j=0; j<song.pat[i].effectCols; j++) {
+  for (int j=0; j<curPat[i].effectCols; j++) {
     short effect=pat->data[whatRow][4+(j<<1)];
     short effectVal=pat->data[whatRow][5+(j<<1)];
 
@@ -548,7 +548,7 @@ void DivEngine::processRow(int i, bool afterDelay) {
         break;
       case 0xe0: // arp speed
         if (effectVal>0) {
-          song.arpLen=effectVal;
+          curSubSong->arpLen=effectVal;
         }
         break;
       case 0xe1: // portamento up
@@ -727,7 +727,7 @@ void DivEngine::processRow(int i, bool afterDelay) {
   chan[i].noteOnInhibit=false;
 
   // post effects
-  for (int j=0; j<song.pat[i].effectCols; j++) {
+  for (int j=0; j<curPat[i].effectCols; j++) {
     short effect=pat->data[whatRow][4+(j<<1)];
     short effectVal=pat->data[whatRow][5+(j<<1)];
 
@@ -745,10 +745,10 @@ void DivEngine::nextRow() {
     strcpy(pb1,"");
     strcpy(pb3,"");
     for (int i=0; i<chans; i++) {
-      snprintf(pb,4095," %.2x",song.orders.ord[i][curOrder]);
+      snprintf(pb,4095," %.2x",curOrders->ord[i][curOrder]);
       strcat(pb1,pb);
       
-      DivPattern* pat=song.pat[i].getPattern(song.orders.ord[i][curOrder],false);
+      DivPattern* pat=curPat[i].getPattern(curOrders->ord[i][curOrder],false);
       snprintf(pb2,4095,"\x1b[37m %s",
               formatNote(pat->data[curRow][0],pat->data[curRow][1]));
       strcat(pb3,pb2);
@@ -764,7 +764,7 @@ void DivEngine::nextRow() {
         snprintf(pb2,4095,"\x1b[0;36m%.2x",pat->data[curRow][2]);
         strcat(pb3,pb2);
       }
-      for (int j=0; j<song.pat[i].effectCols; j++) {
+      for (int j=0; j<curPat[i].effectCols; j++) {
         if (pat->data[curRow][4+(j<<1)]==-1) {
           strcat(pb3,"\x1b[m--");
         } else {
@@ -796,32 +796,32 @@ void DivEngine::nextRow() {
       if (changeOrd==-2) changeOrd=curOrder+1;
       if (changeOrd<=curOrder) endOfSong=true;
       curOrder=changeOrd;
-      if (curOrder>=song.ordersLen) {
+      if (curOrder>=curSubSong->ordersLen) {
         curOrder=0;
         endOfSong=true;
       }
       changeOrd=-1;
     }
     if (haltOn==DIV_HALT_PATTERN) halted=true;
-  } else if (playing) if (++curRow>=song.patLen) {
+  } else if (playing) if (++curRow>=curSubSong->patLen) {
     nextOrder();
     if (haltOn==DIV_HALT_PATTERN) halted=true;
   }
 
   if (song.brokenSpeedSel) {
-    if ((song.patLen&1) && curOrder&1) {
-      ticks=((curRow&1)?speed2:speed1)*(song.timeBase+1);
+    if ((curSubSong->patLen&1) && curOrder&1) {
+      ticks=((curRow&1)?speed2:speed1)*(curSubSong->timeBase+1);
       nextSpeed=(curRow&1)?speed1:speed2;
     } else {
-      ticks=((curRow&1)?speed1:speed2)*(song.timeBase+1);
+      ticks=((curRow&1)?speed1:speed2)*(curSubSong->timeBase+1);
       nextSpeed=(curRow&1)?speed2:speed1;
     }
   } else {
     if (speedAB) {
-      ticks=speed2*(song.timeBase+1);
+      ticks=speed2*(curSubSong->timeBase+1);
       nextSpeed=speed1;
     } else {
-      ticks=speed1*(song.timeBase+1);
+      ticks=speed1*(curSubSong->timeBase+1);
       nextSpeed=speed2;
     }
     speedAB=!speedAB;
@@ -829,7 +829,7 @@ void DivEngine::nextRow() {
 
   // post row details
   for (int i=0; i<chans; i++) {
-    DivPattern* pat=song.pat[i].getPattern(song.orders.ord[i][curOrder],false);
+    DivPattern* pat=curPat[i].getPattern(curOrders->ord[i][curOrder],false);
     if (!(pat->data[curRow][0]==0 && pat->data[curRow][1]==0)) {
       if (pat->data[curRow][0]!=100 && pat->data[curRow][0]!=101 && pat->data[curRow][0]!=102) {
         if (!chan[i].legato) {
@@ -838,7 +838,7 @@ void DivEngine::nextRow() {
           if (song.oneTickCut) {
             bool doPrepareCut=true;
 
-            for (int j=0; j<song.pat[i].effectCols; j++) {
+            for (int j=0; j<curPat[i].effectCols; j++) {
               if (pat->data[curRow][4+(j<<1)]==0x03) {
                 doPrepareCut=false;
                 break;
@@ -1007,7 +1007,7 @@ bool DivEngine::nextTick(bool noAccum, bool inhibitLowLat) {
         }
         if (chan[i].arp!=0 && !chan[i].arpYield && chan[i].portaSpeed<1) {
           if (--chan[i].arpTicks<1) {
-            chan[i].arpTicks=song.arpLen;
+            chan[i].arpTicks=curSubSong->arpLen;
             chan[i].arpStage++;
             if (chan[i].arpStage>2) chan[i].arpStage=0;
             switch (chan[i].arpStage) {
@@ -1048,7 +1048,7 @@ bool DivEngine::nextTick(bool noAccum, bool inhibitLowLat) {
       }
     }
 
-    if (consoleMode && subticks<=1) fprintf(stderr,"\x1b[2K> %d:%.2d:%.2d.%.2d  %.2x/%.2x:%.3d/%.3d  %4dcmd/s\x1b[G",totalSeconds/3600,(totalSeconds/60)%60,totalSeconds%60,totalTicks/10000,curOrder,song.ordersLen,curRow,song.patLen,cmdsPerSecond);
+    if (consoleMode && subticks<=1) fprintf(stderr,"\x1b[2K> %d:%.2d:%.2d.%.2d  %.2x/%.2x:%.3d/%.3d  %4dcmd/s\x1b[G",totalSeconds/3600,(totalSeconds/60)%60,totalSeconds%60,totalTicks/10000,curOrder,curSubSong->ordersLen,curRow,curSubSong->patLen,cmdsPerSecond);
   }
 
   if (haltOn==DIV_HALT_TICK) halted=true;
@@ -1240,11 +1240,11 @@ void DivEngine::nextBuf(float** in, float** out, int inChans, int outChans, unsi
       if (!freelance && stepPlay!=-1 && subticks==1) {
         unsigned int realPos=size-(runLeftG>>MASTER_CLOCK_PREC);
         if (realPos>=size) realPos=size-1;
-        if (song.hilightA>0) {
-          if ((curRow%song.hilightA)==0 && ticks==1) metroTick[realPos]=1;
+        if (curSubSong->hilightA>0) {
+          if ((curRow%curSubSong->hilightA)==0 && ticks==1) metroTick[realPos]=1;
         }
-        if (song.hilightB>0) {
-          if ((curRow%song.hilightB)==0 && ticks==1) metroTick[realPos]=2;
+        if (curSubSong->hilightB>0) {
+          if ((curRow%curSubSong->hilightB)==0 && ticks==1) metroTick[realPos]=2;
         }
       }
       if (nextTick()) {
diff --git a/src/engine/sample.cpp b/src/engine/sample.cpp
index e46c267d1..e8bc0f303 100644
--- a/src/engine/sample.cpp
+++ b/src/engine/sample.cpp
@@ -93,6 +93,18 @@ bool DivSample::initInternal(unsigned char d, int count) {
       dataDPCM=new unsigned char[lengthDPCM];
       memset(dataDPCM,0,lengthDPCM);
       break;
+    case 2: // AICA ADPCM
+      if (dataAICA!=NULL) delete[] dataAICA;
+      lengthAICA=(count+1)/2;
+      dataAICA=new unsigned char[(lengthAICA+255)&(~0xff)];
+      memset(dataAICA,0,(lengthAICA+255)&(~0xff));
+      break;
+    case 3: // YMZ ADPCM
+      if (dataZ!=NULL) delete[] dataZ;
+      lengthZ=(count+1)/2;
+      dataZ=new unsigned char[(lengthZ+255)&(~0xff)];
+      memset(dataZ,0,(lengthZ+255)&(~0xff));
+      break;
     case 4: // QSound ADPCM
       if (dataQSoundA!=NULL) delete[] dataQSoundA;
       lengthQSoundA=(count+1)/2;
@@ -657,6 +669,12 @@ void DivSample::render() {
         }
         break;
       }
+      case 2: // AICA ADPCM
+        aica_decode(dataAICA,data16,samples);
+        break;
+      case 3: // YMZ ADPCM
+        ymz_decode(dataZ,data16,samples);
+        break;
       case 4: // QSound ADPCM
         bs_decode(dataQSoundA,data16,samples);
         break;
@@ -709,6 +727,14 @@ void DivSample::render() {
       if (accum>127) accum=127;
     }
   }
+  if (depth!=2) { // AICA ADPCM
+    if (!initInternal(2,samples)) return;
+    aica_encode(data16,dataAICA,(samples+511)&(~0x1ff));
+  }
+  if (depth!=3) { // YMZ ADPCM
+    if (!initInternal(3,samples)) return;
+    ymz_encode(data16,dataZ,(samples+511)&(~0x1ff));
+  }
   if (depth!=4) { // QSound ADPCM
     if (!initInternal(4,samples)) return;
     bs_encode(data16,dataQSoundA,samples);
@@ -745,6 +771,10 @@ void* DivSample::getCurBuf() {
       return data1;
     case 1:
       return dataDPCM;
+    case 2:
+      return dataAICA;
+    case 3:
+      return dataZ;
     case 4:
       return dataQSoundA;
     case 5:
@@ -771,6 +801,10 @@ unsigned int DivSample::getCurBufLen() {
       return length1;
     case 1:
       return lengthDPCM;
+    case 2:
+      return lengthAICA;
+    case 3:
+      return lengthZ;
     case 4:
       return lengthQSoundA;
     case 5:
@@ -881,6 +915,8 @@ DivSample::~DivSample() {
   if (data16) delete[] data16;
   if (data1) delete[] data1;
   if (dataDPCM) delete[] dataDPCM;
+  if (dataAICA) delete[] dataAICA;
+  if (dataZ) delete[] dataZ;
   if (dataQSoundA) delete[] dataQSoundA;
   if (dataA) delete[] dataA;
   if (dataB) delete[] dataB;
diff --git a/src/engine/sample.h b/src/engine/sample.h
index 6e4de0941..624139797 100644
--- a/src/engine/sample.h
+++ b/src/engine/sample.h
@@ -62,6 +62,8 @@ struct DivSample {
   // valid values are:
   // - 0: ZX Spectrum overlay drum (1-bit)
   // - 1: 1-bit NES DPCM (1-bit)
+  // - 2: AICA ADPCM
+  // - 3: YMZ ADPCM
   // - 4: QSound ADPCM
   // - 5: ADPCM-A
   // - 6: ADPCM-B
@@ -77,6 +79,8 @@ struct DivSample {
   short* data16; // 16
   unsigned char* data1; // 0
   unsigned char* dataDPCM; // 1
+  unsigned char* dataAICA; // 2
+  unsigned char* dataZ; // 3
   unsigned char* dataQSoundA; // 4
   unsigned char* dataA; // 5
   unsigned char* dataB; // 6
@@ -84,8 +88,8 @@ struct DivSample {
   unsigned char* dataBRR; // 9
   unsigned char* dataVOX; // 10
 
-  unsigned int length8, length16, length1, lengthDPCM, lengthQSoundA, lengthA, lengthB, lengthX68, lengthBRR, lengthVOX;
-  unsigned int off8, off16, off1, offDPCM, offQSoundA, offA, offB, offX68, offBRR, offVOX;
+  unsigned int length8, length16, length1, lengthDPCM, lengthAICA, lengthZ, lengthQSoundA, lengthA, lengthB, lengthX68, lengthBRR, lengthVOX;
+  unsigned int off8, off16, off1, offDPCM, offAICA, offZ, offQSoundA, offA, offB, offX68, offBRR, offVOX;
   unsigned int offSegaPCM, offQSound, offX1_010, offSU;
 
   unsigned int samples;
@@ -218,6 +222,8 @@ struct DivSample {
     data16(NULL),
     data1(NULL),
     dataDPCM(NULL),
+    dataAICA(NULL),
+    dataZ(NULL),
     dataQSoundA(NULL),
     dataA(NULL),
     dataB(NULL),
@@ -228,6 +234,8 @@ struct DivSample {
     length16(0),
     length1(0),
     lengthDPCM(0),
+    lengthAICA(0),
+    lengthZ(0),
     lengthQSoundA(0),
     lengthA(0),
     lengthB(0),
@@ -238,6 +246,8 @@ struct DivSample {
     off16(0),
     off1(0),
     offDPCM(0),
+    offAICA(0),
+    offZ(0),
     offQSoundA(0),
     offA(0),
     offB(0),
diff --git a/src/engine/song.cpp b/src/engine/song.cpp
index 7a815eb16..216a1bc4d 100644
--- a/src/engine/song.cpp
+++ b/src/engine/song.cpp
@@ -19,7 +19,7 @@
 
 #include "song.h"
 
-void DivSong::clearSongData() {
+void DivSubSong::clearData() {
   for (int i=0; i<DIV_MAX_CHANS; i++) {
     pat[i].wipePatterns();
   }
@@ -28,6 +28,15 @@ void DivSong::clearSongData() {
   ordersLen=1;
 }
 
+void DivSong::clearSongData() {
+  for (DivSubSong* i: subsong) {
+    i->clearData();
+    delete i;
+  }
+  subsong.clear();
+  subsong.push_back(new DivSubSong);
+}
+
 void DivSong::clearInstruments() {
   for (DivInstrument* i: ins) {
     delete i;
@@ -71,7 +80,9 @@ void DivSong::unload() {
   sample.clear();
   sampleLen=0;
 
-  for (int i=0; i<DIV_MAX_CHANS; i++) {
-    pat[i].wipePatterns();
+  for (DivSubSong* i: subsong) {
+    i->clearData();
+    delete i;
   }
+  subsong.clear();
 }
diff --git a/src/engine/song.h b/src/engine/song.h
index e4f003542..219225e8f 100644
--- a/src/engine/song.h
+++ b/src/engine/song.h
@@ -110,6 +110,44 @@ enum DivSystem {
   DIV_SYSTEM_DUMMY
 };
 
+struct DivSubSong {
+  String name, notes;
+  unsigned char hilightA, hilightB;
+  unsigned char timeBase, speed1, speed2, arpLen;
+  bool pal;
+  bool customTempo;
+  float hz;
+  int patLen, ordersLen;
+
+  DivOrders orders;
+  DivChannelData pat[DIV_MAX_CHANS];
+
+  bool chanShow[DIV_MAX_CHANS];
+  unsigned char chanCollapse[DIV_MAX_CHANS];
+  String chanName[DIV_MAX_CHANS];
+  String chanShortName[DIV_MAX_CHANS];
+
+  void clearData();
+
+  DivSubSong(): 
+    hilightA(4),
+    hilightB(16),
+    timeBase(0),
+    speed1(6),
+    speed2(6),
+    arpLen(1),
+    pal(true),
+    customTempo(false),
+    hz(60.0),
+    patLen(64),
+    ordersLen(1) {
+    for (int i=0; i<DIV_MAX_CHANS; i++) {
+      chanShow[i]=true;
+      chanCollapse[i]=0;
+    }
+  }
+};
+
 struct DivSong {
   // version number used for saving the song.
   // Furnace will save using the latest possible version,
@@ -156,14 +194,21 @@ struct DivSong {
   //   - introduces Genesis system
   //   - introduces system number
   //   - patterns now stored in current known format
+  // - 8: ???
+  //   - only used in the Medivo YMU cover
   // - 7: ???
+  //   - only present in a later version of First.dmf
+  //   - pattern format changes: empty field is 0xFF instead of 0x80
+  //   - instrument now stored in pattern
   // - 5: BETA 3
   //   - adds arpeggio tick
   // - 4: BETA 2
+  //   - possibly adds instrument number (stored in channel)?
+  //   - cannot confirm as I don't have any version 4 modules
   // - 3: BETA 1
   //   - possibly the first version that could save
   //   - basic format, no system number, 16 instruments, one speed, YMU759-only
-  //   - patterns were stored in a different format (chars instead of shorts)
+  //   - patterns were stored in a different format (chars instead of shorts) and no instrument
   //   - if somebody manages to find a version 2 or even 1 module, please tell me as it will be worth more than a luxury vehicle
   unsigned short version;
   bool isDMF;
@@ -285,19 +330,10 @@ struct DivSong {
   String nameJ, authorJ, categoryJ;
 
   // other things
-  String chanName[DIV_MAX_CHANS];
-  String chanShortName[DIV_MAX_CHANS];
   String notes;
 
-  // highlight
-  unsigned char hilightA, hilightB;
-
   // module details
-  unsigned char timeBase, speed1, speed2, arpLen;
-  bool pal;
-  bool customTempo;
-  float hz;
-  int patLen, ordersLen, insLen, waveLen, sampleLen;
+  int insLen, waveLen, sampleLen;
   float masterVol;
   float tuning;
 
@@ -345,14 +381,11 @@ struct DivSong {
   bool snDutyReset;
   bool pitchMacroIsLinear;
 
-  DivOrders orders;
   std::vector<DivInstrument*> ins;
-  DivChannelData pat[DIV_MAX_CHANS];
   std::vector<DivWavetable*> wave;
   std::vector<DivSample*> sample;
 
-  bool chanShow[DIV_MAX_CHANS];
-  unsigned char chanCollapse[DIV_MAX_CHANS];
+  std::vector<DivSubSong*> subsong;
 
   DivInstrument nullIns, nullInsOPLL, nullInsOPL, nullInsQSound;
   DivWavetable nullWave;
@@ -401,17 +434,6 @@ struct DivSong {
     manInfo(""),
     createdDate(""),
     revisionDate(""),
-    hilightA(4),
-    hilightB(16),
-    timeBase(0),
-    speed1(6),
-    speed2(6),
-    arpLen(1),
-    pal(true),
-    customTempo(false),
-    hz(60.0),
-    patLen(64),
-    ordersLen(1),
     insLen(0),
     waveLen(0),
     sampleLen(0),
@@ -457,10 +479,7 @@ struct DivSong {
       systemPan[i]=0;
       systemFlags[i]=0;
     }
-    for (int i=0; i<DIV_MAX_CHANS; i++) {
-      chanShow[i]=true;
-      chanCollapse[i]=0;
-    }
+    subsong.push_back(new DivSubSong);
     system[0]=DIV_SYSTEM_YM2612;
     system[1]=DIV_SYSTEM_SMS;
 
diff --git a/src/engine/sysDef.cpp b/src/engine/sysDef.cpp
index 2c90142e0..10f8907f4 100644
--- a/src/engine/sysDef.cpp
+++ b/src/engine/sysDef.cpp
@@ -283,7 +283,7 @@ bool DivEngine::isSTDSystem(DivSystem sys) {
 
 const char* DivEngine::getChannelName(int chan) {
   if (chan<0 || chan>chans) return "??";
-  if (!song.chanName[chan].empty()) return song.chanName[chan].c_str();
+  if (!curSubSong->chanName[chan].empty()) return curSubSong->chanName[chan].c_str();
   if (sysDefs[sysOfChan[chan]]==NULL) return "??";
   
   const char* ret=sysDefs[sysOfChan[chan]]->chanNames[dispatchChanOfChan[chan]];
@@ -293,7 +293,7 @@ const char* DivEngine::getChannelName(int chan) {
 
 const char* DivEngine::getChannelShortName(int chan) {
   if (chan<0 || chan>chans) return "??";
-  if (!song.chanShortName[chan].empty()) return song.chanShortName[chan].c_str();
+  if (!curSubSong->chanShortName[chan].empty()) return curSubSong->chanShortName[chan].c_str();
   if (sysDefs[sysOfChan[chan]]==NULL) return "??";
   
   const char* ret=sysDefs[sysOfChan[chan]]->chanShortNames[dispatchChanOfChan[chan]];
diff --git a/src/gui/actionUtil.h b/src/gui/actionUtil.h
index 752a54423..81685af48 100644
--- a/src/gui/actionUtil.h
+++ b/src/gui/actionUtil.h
@@ -20,7 +20,7 @@
 #define DETERMINE_FIRST \
   int firstChannel=0; \
   for (int i=0; i<e->getTotalChannelCount(); i++) { \
-    if (e->song.chanShow[i]) { \
+    if (e->curSubSong->chanShow[i]) { \
       firstChannel=i; \
       break; \
     } \
@@ -29,7 +29,7 @@
 #define DETERMINE_LAST \
   int lastChannel=0; \
   for (int i=e->getTotalChannelCount()-1; i>=0; i--) { \
-    if (e->song.chanShow[i]) { \
+    if (e->curSubSong->chanShow[i]) { \
       lastChannel=i+1; \
       break; \
     } \
diff --git a/src/gui/channels.cpp b/src/gui/channels.cpp
index 397ac2f65..c88075611 100644
--- a/src/gui/channels.cpp
+++ b/src/gui/channels.cpp
@@ -38,7 +38,7 @@ void FurnaceGUI::drawChannels() {
         ImGui::PushID(i);
         ImGui::TableNextRow();
         ImGui::TableNextColumn();
-        ImGui::Checkbox("##Visible",&e->song.chanShow[i]);
+        ImGui::Checkbox("##Visible",&e->curSubSong->chanShow[i]);
         ImGui::SameLine();
         ImGui::BeginDisabled(i==0);
         if (ImGui::Button(ICON_FA_CHEVRON_UP)) {
@@ -53,10 +53,10 @@ void FurnaceGUI::drawChannels() {
         ImGui::EndDisabled();
         ImGui::TableNextColumn();
         ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
-        ImGui::InputTextWithHint("##ChanName",e->getChannelName(i),&e->song.chanName[i]);
+        ImGui::InputTextWithHint("##ChanName",e->getChannelName(i),&e->curSubSong->chanName[i]);
         ImGui::TableNextColumn();
         ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
-        ImGui::InputTextWithHint("##ChanShortName",e->getChannelShortName(i),&e->song.chanShortName[i]);
+        ImGui::InputTextWithHint("##ChanShortName",e->getChannelShortName(i),&e->curSubSong->chanShortName[i]);
         ImGui::PopID();
       }
       ImGui::EndTable();
diff --git a/src/gui/cursor.cpp b/src/gui/cursor.cpp
index 972beee02..244880735 100644
--- a/src/gui/cursor.cpp
+++ b/src/gui/cursor.cpp
@@ -32,7 +32,7 @@ void FurnaceGUI::startSelection(int xCoarse, int xFine, int y, bool fullRow) {
     selStart.xCoarse=firstChannel;
     selStart.xFine=0;
     selEnd.xCoarse=lastChannel-1;
-    selEnd.xFine=2+e->song.pat[selEnd.xCoarse].effectCols*2;
+    selEnd.xFine=2+e->curPat[selEnd.xCoarse].effectCols*2;
     selStart.y=y;
     selEnd.y=y;
   } else {
@@ -56,7 +56,7 @@ void FurnaceGUI::updateSelection(int xCoarse, int xFine, int y, bool fullRow) {
   if (selectingFull) {
     DETERMINE_LAST;
     selEnd.xCoarse=lastChannel-1;
-    selEnd.xFine=2+e->song.pat[selEnd.xCoarse].effectCols*2;
+    selEnd.xFine=2+e->curPat[selEnd.xCoarse].effectCols*2;
     selEnd.y=y;
   } else {
     selEnd.xCoarse=xCoarse;
@@ -94,21 +94,21 @@ void FurnaceGUI::finishSelection() {
   if (selStart.xCoarse<0) selStart.xCoarse=0;
   if (selStart.xCoarse>=chanCount) selStart.xCoarse=chanCount-1;
   if (selStart.y<0) selStart.y=0;
-  if (selStart.y>=e->song.patLen) selStart.y=e->song.patLen-1;
+  if (selStart.y>=e->curSubSong->patLen) selStart.y=e->curSubSong->patLen-1;
   if (selEnd.xCoarse<0) selEnd.xCoarse=0;
   if (selEnd.xCoarse>=chanCount) selEnd.xCoarse=chanCount-1;
   if (selEnd.y<0) selEnd.y=0;
-  if (selEnd.y>=e->song.patLen) selEnd.y=e->song.patLen-1;
+  if (selEnd.y>=e->curSubSong->patLen) selEnd.y=e->curSubSong->patLen-1;
   if (cursor.xCoarse<0) cursor.xCoarse=0;
   if (cursor.xCoarse>=chanCount) cursor.xCoarse=chanCount-1;
   if (cursor.y<0) cursor.y=0;
-  if (cursor.y>=e->song.patLen) cursor.y=e->song.patLen-1;
+  if (cursor.y>=e->curSubSong->patLen) cursor.y=e->curSubSong->patLen-1;
 
-  if (e->song.chanCollapse[selStart.xCoarse]==3) {
+  if (e->curSubSong->chanCollapse[selStart.xCoarse]==3) {
     selStart.xFine=0;
   }
-  if (e->song.chanCollapse[selEnd.xCoarse] && selEnd.xFine>=(3-e->song.chanCollapse[selEnd.xCoarse])) {
-    selEnd.xFine=2+e->song.pat[cursor.xCoarse].effectCols*2;
+  if (e->curSubSong->chanCollapse[selEnd.xCoarse] && selEnd.xFine>=(3-e->curSubSong->chanCollapse[selEnd.xCoarse])) {
+    selEnd.xFine=2+e->curPat[cursor.xCoarse].effectCols*2;
   }
 
   e->setMidiBaseChan(cursor.xCoarse);
@@ -126,7 +126,7 @@ void FurnaceGUI::moveCursor(int x, int y, bool select) {
     demandScrollX=true;
     if (x>0) {
       for (int i=0; i<x; i++) {
-        if (++cursor.xFine>=(e->song.chanCollapse[cursor.xCoarse]?(4-e->song.chanCollapse[cursor.xCoarse]):(3+e->song.pat[cursor.xCoarse].effectCols*2))) {
+        if (++cursor.xFine>=(e->curSubSong->chanCollapse[cursor.xCoarse]?(4-e->curSubSong->chanCollapse[cursor.xCoarse]):(3+e->curPat[cursor.xCoarse].effectCols*2))) {
           cursor.xFine=0;
           if (++cursor.xCoarse>=lastChannel) {
             if (settings.wrapHorizontal!=0 && !select) {
@@ -134,10 +134,10 @@ void FurnaceGUI::moveCursor(int x, int y, bool select) {
               if (settings.wrapHorizontal==2) y++;
             } else {
               cursor.xCoarse=lastChannel-1;
-              cursor.xFine=e->song.chanCollapse[cursor.xCoarse]?(3-e->song.chanCollapse[cursor.xCoarse]):(2+e->song.pat[cursor.xCoarse].effectCols*2);
+              cursor.xFine=e->curSubSong->chanCollapse[cursor.xCoarse]?(3-e->curSubSong->chanCollapse[cursor.xCoarse]):(2+e->curPat[cursor.xCoarse].effectCols*2);
             }
           } else {
-            while (!e->song.chanShow[cursor.xCoarse]) {
+            while (!e->curSubSong->chanShow[cursor.xCoarse]) {
               cursor.xCoarse++;
               if (cursor.xCoarse>=e->getTotalChannelCount()) break;
             }
@@ -150,21 +150,21 @@ void FurnaceGUI::moveCursor(int x, int y, bool select) {
           if (--cursor.xCoarse<firstChannel) {
             if (settings.wrapHorizontal!=0 && !select) {
               cursor.xCoarse=lastChannel-1;
-              cursor.xFine=2+e->song.pat[cursor.xCoarse].effectCols*2;
+              cursor.xFine=2+e->curPat[cursor.xCoarse].effectCols*2;
               if (settings.wrapHorizontal==2) y--;
             } else {
               cursor.xCoarse=firstChannel;
               cursor.xFine=0;
             }
           } else {
-            while (!e->song.chanShow[cursor.xCoarse]) {
+            while (!e->curSubSong->chanShow[cursor.xCoarse]) {
               cursor.xCoarse--;
               if (cursor.xCoarse<0) break;
             }
-            if (e->song.chanCollapse[cursor.xCoarse]) {
-              cursor.xFine=3-e->song.chanCollapse[cursor.xCoarse];
+            if (e->curSubSong->chanCollapse[cursor.xCoarse]) {
+              cursor.xFine=3-e->curSubSong->chanCollapse[cursor.xCoarse];
             } else {
-              cursor.xFine=2+e->song.pat[cursor.xCoarse].effectCols*2;
+              cursor.xFine=2+e->curPat[cursor.xCoarse].effectCols*2;
             }
           }
         }
@@ -175,18 +175,18 @@ void FurnaceGUI::moveCursor(int x, int y, bool select) {
     if (y>0) {
       for (int i=0; i<y; i++) {
         cursor.y++;
-        if (cursor.y>=e->song.patLen) {
+        if (cursor.y>=e->curSubSong->patLen) {
           if (settings.wrapVertical!=0 && !select) {
             cursor.y=0;
             if (settings.wrapVertical==2) {
-              if ((!e->isPlaying() || !followPattern) && curOrder<(e->song.ordersLen-1)) {
+              if ((!e->isPlaying() || !followPattern) && curOrder<(e->curSubSong->ordersLen-1)) {
                 setOrder(curOrder+1);
               } else {
-                cursor.y=e->song.patLen-1;
+                cursor.y=e->curSubSong->patLen-1;
               }
             }
           } else {
-            cursor.y=e->song.patLen-1;
+            cursor.y=e->curSubSong->patLen-1;
           }
         }
       }
@@ -195,7 +195,7 @@ void FurnaceGUI::moveCursor(int x, int y, bool select) {
         cursor.y--;
         if (cursor.y<0) {
           if (settings.wrapVertical!=0 && !select) {
-            cursor.y=e->song.patLen-1;
+            cursor.y=e->curSubSong->patLen-1;
             if (settings.wrapVertical==2) {
               if ((!e->isPlaying() || !followPattern) && curOrder>0) {
                 setOrder(curOrder-1);
@@ -229,7 +229,7 @@ void FurnaceGUI::moveCursorPrevChannel(bool overflow) {
   do {
     cursor.xCoarse--;
     if (cursor.xCoarse<0) break;
-  } while (!e->song.chanShow[cursor.xCoarse]);
+  } while (!e->curSubSong->chanShow[cursor.xCoarse]);
   if (cursor.xCoarse<firstChannel) {
     if (overflow) {
       cursor.xCoarse=lastChannel-1;
@@ -253,7 +253,7 @@ void FurnaceGUI::moveCursorNextChannel(bool overflow) {
   do {
     cursor.xCoarse++;
     if (cursor.xCoarse>=e->getTotalChannelCount()) break;
-  } while (!e->song.chanShow[cursor.xCoarse]);
+  } while (!e->curSubSong->chanShow[cursor.xCoarse]);
   if (cursor.xCoarse>=lastChannel) {
     if (overflow) {
       cursor.xCoarse=firstChannel;
@@ -290,14 +290,14 @@ void FurnaceGUI::moveCursorTop(bool select) {
 void FurnaceGUI::moveCursorBottom(bool select) {
   finishSelection();
   curNibble=false;
-  if (cursor.y==e->song.patLen-1) {
+  if (cursor.y==e->curSubSong->patLen-1) {
     DETERMINE_LAST;
     cursor.xCoarse=lastChannel-1;
     if (cursor.xCoarse<0) cursor.xCoarse=0;
-    cursor.xFine=2+e->song.pat[cursor.xCoarse].effectCols*2;
+    cursor.xFine=2+e->curPat[cursor.xCoarse].effectCols*2;
     demandScrollX=true;
   } else {
-    cursor.y=e->song.patLen-1;
+    cursor.y=e->curSubSong->patLen-1;
   }
   if (!select) {
     selStart=cursor;
@@ -310,7 +310,7 @@ void FurnaceGUI::moveCursorBottom(bool select) {
 void FurnaceGUI::editAdvance() {
   finishSelection();
   cursor.y+=editStep;
-  if (cursor.y>=e->song.patLen) cursor.y=e->song.patLen-1;
+  if (cursor.y>=e->curSubSong->patLen) cursor.y=e->curSubSong->patLen-1;
   selStart=cursor;
   selEnd=cursor;
   updateScroll(cursor.y);
diff --git a/src/gui/doAction.cpp b/src/gui/doAction.cpp
index 2e1dd3779..9a364e233 100644
--- a/src/gui/doAction.cpp
+++ b/src/gui/doAction.cpp
@@ -470,7 +470,7 @@ void FurnaceGUI::doAction(int what) {
       e->unmuteAll();
       break;
     case GUI_ACTION_PAT_NEXT_ORDER:
-      if (curOrder<e->song.ordersLen-1) {
+      if (curOrder<e->curSubSong->ordersLen-1) {
         setOrder(curOrder+1);
       }
       break;
@@ -481,21 +481,21 @@ void FurnaceGUI::doAction(int what) {
       break;
     case GUI_ACTION_PAT_COLLAPSE:
       if (cursor.xCoarse<0 || cursor.xCoarse>=e->getTotalChannelCount()) break;
-      if (e->song.chanCollapse[cursor.xCoarse]==0) {
-        e->song.chanCollapse[cursor.xCoarse]=3;
-      } else if (e->song.chanCollapse[cursor.xCoarse]>0) {
-        e->song.chanCollapse[cursor.xCoarse]--;
+      if (e->curSubSong->chanCollapse[cursor.xCoarse]==0) {
+        e->curSubSong->chanCollapse[cursor.xCoarse]=3;
+      } else if (e->curSubSong->chanCollapse[cursor.xCoarse]>0) {
+        e->curSubSong->chanCollapse[cursor.xCoarse]--;
       }
       break;
     case GUI_ACTION_PAT_INCREASE_COLUMNS:
       if (cursor.xCoarse<0 || cursor.xCoarse>=e->getTotalChannelCount()) break;
-      e->song.pat[cursor.xCoarse].effectCols++;
-              if (e->song.pat[cursor.xCoarse].effectCols>8) e->song.pat[cursor.xCoarse].effectCols=8;
+      e->curPat[cursor.xCoarse].effectCols++;
+              if (e->curPat[cursor.xCoarse].effectCols>8) e->curPat[cursor.xCoarse].effectCols=8;
       break;
     case GUI_ACTION_PAT_DECREASE_COLUMNS:
       if (cursor.xCoarse<0 || cursor.xCoarse>=e->getTotalChannelCount()) break;
-      e->song.pat[cursor.xCoarse].effectCols--;
-      if (e->song.pat[cursor.xCoarse].effectCols<1) e->song.pat[cursor.xCoarse].effectCols=1;
+      e->curPat[cursor.xCoarse].effectCols--;
+      if (e->curPat[cursor.xCoarse].effectCols<1) e->curPat[cursor.xCoarse].effectCols=1;
       break;
     case GUI_ACTION_PAT_INTERPOLATE:
       doInterpolate();
@@ -525,14 +525,22 @@ void FurnaceGUI::doAction(int what) {
 
     case GUI_ACTION_INS_LIST_ADD:
       curIns=e->addInstrument(cursor.xCoarse);
-      MARK_MODIFIED;
+      if (curIns==-1) {
+        showError("too many instruments!");
+      } else {
+        MARK_MODIFIED;
+      }
       break;
     case GUI_ACTION_INS_LIST_DUPLICATE:
       if (curIns>=0 && curIns<(int)e->song.ins.size()) {
         int prevIns=curIns;
         curIns=e->addInstrument(cursor.xCoarse);
-        (*e->song.ins[curIns])=(*e->song.ins[prevIns]);
-        MARK_MODIFIED;
+        if (curIns==-1) {
+          showError("too many instruments!");
+        } else {
+          (*e->song.ins[curIns])=(*e->song.ins[prevIns]);
+          MARK_MODIFIED;
+        }
       }
       break;
     case GUI_ACTION_INS_LIST_OPEN:
@@ -571,14 +579,22 @@ void FurnaceGUI::doAction(int what) {
     
     case GUI_ACTION_WAVE_LIST_ADD:
       curWave=e->addWave();
-      MARK_MODIFIED;
+      if (curWave==-1) {
+        showError("too many wavetables!");
+      } else {
+        MARK_MODIFIED;
+      }
       break;
     case GUI_ACTION_WAVE_LIST_DUPLICATE:
       if (curWave>=0 && curWave<(int)e->song.wave.size()) {
         int prevWave=curWave;
         curWave=e->addWave();
-        (*e->song.wave[curWave])=(*e->song.wave[prevWave]);
-        MARK_MODIFIED;
+        if (curWave==-1) {
+          showError("too many wavetables!");
+        } else {
+          (*e->song.wave[curWave])=(*e->song.wave[prevWave]);
+          MARK_MODIFIED;
+        }
       }
       break;
     case GUI_ACTION_WAVE_LIST_OPEN:
@@ -614,31 +630,39 @@ void FurnaceGUI::doAction(int what) {
 
     case GUI_ACTION_SAMPLE_LIST_ADD:
       curSample=e->addSample();
+      if (curSample==-1) {
+        showError("too many samples!");
+      } else {
+        MARK_MODIFIED;
+      }
       updateSampleTex=true;
-      MARK_MODIFIED;
       break;
     case GUI_ACTION_SAMPLE_LIST_DUPLICATE:
       if (curSample>=0 && curSample<(int)e->song.sample.size()) {
         DivSample* prevSample=e->getSample(curSample);
         curSample=e->addSample();
-        updateSampleTex=true;
-        e->lockEngine([this,prevSample]() {
-          DivSample* sample=e->getSample(curSample);
-          if (sample!=NULL) {
-            sample->rate=prevSample->rate;
-            sample->centerRate=prevSample->centerRate;
-            sample->name=prevSample->name;
-            sample->loopStart=prevSample->loopStart;
-            sample->depth=prevSample->depth;
-            if (sample->init(prevSample->samples)) {
-              if (prevSample->getCurBuf()!=NULL) {
-                memcpy(sample->getCurBuf(),prevSample->getCurBuf(),prevSample->getCurBufLen());
+        if (curSample==-1) {
+          showError("too many samples!");
+        } else {
+          e->lockEngine([this,prevSample]() {
+            DivSample* sample=e->getSample(curSample);
+            if (sample!=NULL) {
+              sample->rate=prevSample->rate;
+              sample->centerRate=prevSample->centerRate;
+              sample->name=prevSample->name;
+              sample->loopStart=prevSample->loopStart;
+              sample->depth=prevSample->depth;
+              if (sample->init(prevSample->samples)) {
+                if (prevSample->getCurBuf()!=NULL) {
+                  memcpy(sample->getCurBuf(),prevSample->getCurBuf(),prevSample->getCurBufLen());
+                }
               }
             }
-          }
-          e->renderSamples();
-        });
-        MARK_MODIFIED;
+            e->renderSamples();
+          });
+          MARK_MODIFIED;
+        }
+        updateSampleTex=true;
       }
       break;
     case GUI_ACTION_SAMPLE_LIST_OPEN:
@@ -1154,11 +1178,15 @@ void FurnaceGUI::doAction(int what) {
       if (curSample<0 || curSample>=(int)e->song.sample.size()) break;
       DivSample* sample=e->song.sample[curSample];
       curIns=e->addInstrument(cursor.xCoarse);
-      e->song.ins[curIns]->type=DIV_INS_AMIGA;
-      e->song.ins[curIns]->name=sample->name;
-      e->song.ins[curIns]->amiga.initSample=curSample;
-      nextWindow=GUI_WINDOW_INS_EDIT;
-      MARK_MODIFIED;
+      if (curIns==-1) {
+        showError("too many instruments!");
+      } else {
+        e->song.ins[curIns]->type=DIV_INS_AMIGA;
+        e->song.ins[curIns]->name=sample->name;
+        e->song.ins[curIns]->amiga.initSample=curSample;
+        nextWindow=GUI_WINDOW_INS_EDIT;
+        MARK_MODIFIED;
+      }
       break;
     }
 
@@ -1168,7 +1196,7 @@ void FurnaceGUI::doAction(int what) {
       }
       break;
     case GUI_ACTION_ORDERS_DOWN:
-      if (curOrder<e->song.ordersLen-1) {
+      if (curOrder<e->curSubSong->ordersLen-1) {
         setOrder(curOrder+1);
       }
       break;
@@ -1181,7 +1209,7 @@ void FurnaceGUI::doAction(int what) {
           orderCursor=firstChannel;
           break;
         }
-      } while (!e->song.chanShow[orderCursor]);
+      } while (!e->curSubSong->chanShow[orderCursor]);
       break;
     }
     case GUI_ACTION_ORDERS_RIGHT: {
@@ -1193,20 +1221,20 @@ void FurnaceGUI::doAction(int what) {
           orderCursor=lastChannel-1;
           break;
         }
-      } while (!e->song.chanShow[orderCursor]);
+      } while (!e->curSubSong->chanShow[orderCursor]);
       break;
     }
     case GUI_ACTION_ORDERS_INCREASE: {
       if (orderCursor<0 || orderCursor>=e->getTotalChannelCount()) break;
-      if (e->song.orders.ord[orderCursor][curOrder]<0x7f) {
-        e->song.orders.ord[orderCursor][curOrder]++;
+      if (e->curOrders->ord[orderCursor][curOrder]<0x7f) {
+        e->curOrders->ord[orderCursor][curOrder]++;
       }
       break;
     }
     case GUI_ACTION_ORDERS_DECREASE: {
       if (orderCursor<0 || orderCursor>=e->getTotalChannelCount()) break;
-      if (e->song.orders.ord[orderCursor][curOrder]>0) {
-        e->song.orders.ord[orderCursor][curOrder]--;
+      if (e->curOrders->ord[orderCursor][curOrder]>0) {
+        e->curOrders->ord[orderCursor][curOrder]--;
       }
       break;
     }
diff --git a/src/gui/editControls.cpp b/src/gui/editControls.cpp
index 722c38f2a..199a7de00 100644
--- a/src/gui/editControls.cpp
+++ b/src/gui/editControls.cpp
@@ -45,7 +45,7 @@ void FurnaceGUI::drawEditControls() {
         ImGui::Text("Edit Step");
         ImGui::SameLine();
         if (ImGui::InputInt("##EditStep",&editStep,1,1)) {
-          if (editStep>=e->song.patLen) editStep=e->song.patLen-1;
+          if (editStep>=e->curSubSong->patLen) editStep=e->curSubSong->patLen-1;
           if (editStep<0) editStep=0;
 
           if (settings.insFocusesPattern && !ImGui::IsItemActive() && patternOpen) {
@@ -148,7 +148,7 @@ void FurnaceGUI::drawEditControls() {
         ImGui::SameLine();
         ImGui::SetNextItemWidth(96.0f*dpiScale);
         if (ImGui::InputInt("##EditStep",&editStep,1,1)) {
-          if (editStep>=e->song.patLen) editStep=e->song.patLen-1;
+          if (editStep>=e->curSubSong->patLen) editStep=e->curSubSong->patLen-1;
           if (editStep<0) editStep=0;
 
           if (settings.insFocusesPattern && !ImGui::IsItemActive() && patternOpen) {
@@ -217,7 +217,7 @@ void FurnaceGUI::drawEditControls() {
         ImGui::Text("Step");
         ImGui::SetNextItemWidth(avail);
         if (ImGui::InputInt("##EditStep",&editStep,0,0)) {
-          if (editStep>=e->song.patLen) editStep=e->song.patLen-1;
+          if (editStep>=e->curSubSong->patLen) editStep=e->curSubSong->patLen-1;
           if (editStep<0) editStep=0;
 
           if (settings.insFocusesPattern && !ImGui::IsItemActive() && patternOpen) {
@@ -317,7 +317,7 @@ void FurnaceGUI::drawEditControls() {
         ImGui::SetCursorPosX(cursor);
         ImGui::SetNextItemWidth(avail);
         if (ImGui::InputInt("##EditStep",&editStep,1,1)) {
-          if (editStep>=e->song.patLen) editStep=e->song.patLen-1;
+          if (editStep>=e->curSubSong->patLen) editStep=e->curSubSong->patLen-1;
           if (editStep<0) editStep=0;
 
           if (settings.insFocusesPattern && !ImGui::IsItemActive() && patternOpen) {
diff --git a/src/gui/editing.cpp b/src/gui/editing.cpp
index 8832b7fbb..ea12eb591 100644
--- a/src/gui/editing.cpp
+++ b/src/gui/editing.cpp
@@ -44,8 +44,8 @@ const char* noteNameNormal(short note, short octave) {
 void FurnaceGUI::prepareUndo(ActionType action) {
   switch (action) {
     case GUI_UNDO_CHANGE_ORDER:
-      oldOrders=e->song.orders;
-      oldOrdersLen=e->song.ordersLen;
+      memcpy(&oldOrders,e->curOrders,sizeof(DivOrders));
+      oldOrdersLen=e->curSubSong->ordersLen;
       break;
     case GUI_UNDO_PATTERN_EDIT:
     case GUI_UNDO_PATTERN_DELETE:
@@ -63,7 +63,7 @@ void FurnaceGUI::prepareUndo(ActionType action) {
     case GUI_UNDO_PATTERN_COLLAPSE:
     case GUI_UNDO_PATTERN_EXPAND:
       for (int i=0; i<e->getTotalChannelCount(); i++) {
-        e->song.pat[i].getPattern(e->song.orders.ord[i][curOrder],false)->copyOn(oldPat[i]);
+        e->curPat[i].getPattern(e->curOrders->ord[i][curOrder],false)->copyOn(oldPat[i]);
       }
       break;
   }
@@ -78,18 +78,19 @@ void FurnaceGUI::makeUndo(ActionType action) {
   s.selEnd=selEnd;
   s.order=curOrder;
   s.nibble=curNibble;
+  size_t subSong=e->getCurrentSubSong();
   switch (action) {
     case GUI_UNDO_CHANGE_ORDER:
       for (int i=0; i<DIV_MAX_CHANS; i++) {
         for (int j=0; j<128; j++) {
-          if (oldOrders.ord[i][j]!=e->song.orders.ord[i][j]) {
-            s.ord.push_back(UndoOrderData(i,j,oldOrders.ord[i][j],e->song.orders.ord[i][j]));
+          if (oldOrders.ord[i][j]!=e->curOrders->ord[i][j]) {
+            s.ord.push_back(UndoOrderData(subSong,i,j,oldOrders.ord[i][j],e->curOrders->ord[i][j]));
           }
         }
       }
       s.oldOrdersLen=oldOrdersLen;
-      s.newOrdersLen=e->song.ordersLen;
-      if (oldOrdersLen!=e->song.ordersLen) {
+      s.newOrdersLen=e->curSubSong->ordersLen;
+      if (oldOrdersLen!=e->curSubSong->ordersLen) {
         doPush=true;
       }
       if (!s.ord.empty()) {
@@ -112,11 +113,11 @@ void FurnaceGUI::makeUndo(ActionType action) {
     case GUI_UNDO_PATTERN_COLLAPSE:
     case GUI_UNDO_PATTERN_EXPAND:
       for (int i=0; i<e->getTotalChannelCount(); i++) {
-        DivPattern* p=e->song.pat[i].getPattern(e->song.orders.ord[i][curOrder],false);
-        for (int j=0; j<e->song.patLen; j++) {
+        DivPattern* p=e->curPat[i].getPattern(e->curOrders->ord[i][curOrder],false);
+        for (int j=0; j<e->curSubSong->patLen; j++) {
           for (int k=0; k<32; k++) {
             if (p->data[j][k]!=oldPat[i]->data[j][k]) {
-              s.pat.push_back(UndoPatternData(i,e->song.orders.ord[i][curOrder],j,k,oldPat[i]->data[j][k],p->data[j][k]));
+              s.pat.push_back(UndoPatternData(subSong,i,e->curOrders->ord[i][curOrder],j,k,oldPat[i]->data[j][k],p->data[j][k]));
             }
           }
         }
@@ -137,15 +138,15 @@ void FurnaceGUI::makeUndo(ActionType action) {
 void FurnaceGUI::doSelectAll() {
   finishSelection();
   curNibble=false;
-  if (selStart.xFine==0 && selEnd.xFine==2+e->song.pat[selEnd.xCoarse].effectCols*2) {
-    if (selStart.y==0 && selEnd.y==e->song.patLen-1) { // select entire pattern
+  if (selStart.xFine==0 && selEnd.xFine==2+e->curPat[selEnd.xCoarse].effectCols*2) {
+    if (selStart.y==0 && selEnd.y==e->curSubSong->patLen-1) { // select entire pattern
       selStart.xCoarse=0;
       selStart.xFine=0;
       selEnd.xCoarse=e->getTotalChannelCount()-1;
-      selEnd.xFine=2+e->song.pat[selEnd.xCoarse].effectCols*2;
+      selEnd.xFine=2+e->curPat[selEnd.xCoarse].effectCols*2;
     } else { // select entire column
       selStart.y=0;
-      selEnd.y=e->song.patLen-1;
+      selEnd.y=e->curSubSong->patLen-1;
     }
   } else {
     int selStartX=0;
@@ -153,26 +154,26 @@ void FurnaceGUI::doSelectAll() {
     // find row position
     for (SelectionPoint i; i.xCoarse!=selStart.xCoarse || i.xFine!=selStart.xFine; selStartX++) {
       i.xFine++;
-      if (i.xFine>=3+e->song.pat[i.xCoarse].effectCols*2) {
+      if (i.xFine>=3+e->curPat[i.xCoarse].effectCols*2) {
         i.xFine=0;
         i.xCoarse++;
       }
     }
     for (SelectionPoint i; i.xCoarse!=selEnd.xCoarse || i.xFine!=selEnd.xFine; selEndX++) {
       i.xFine++;
-      if (i.xFine>=3+e->song.pat[i.xCoarse].effectCols*2) {
+      if (i.xFine>=3+e->curPat[i.xCoarse].effectCols*2) {
         i.xFine=0;
         i.xCoarse++;
       }
     }
 
     float aspect=float(selEndX-selStartX+1)/float(selEnd.y-selStart.y+1);
-    if (aspect<=1.0f && !(selStart.y==0 && selEnd.y==e->song.patLen-1)) { // up-down
+    if (aspect<=1.0f && !(selStart.y==0 && selEnd.y==e->curSubSong->patLen-1)) { // up-down
       selStart.y=0;
-      selEnd.y=e->song.patLen-1;
+      selEnd.y=e->curSubSong->patLen-1;
     } else { // left-right
       selStart.xFine=0;
-      selEnd.xFine=2+e->song.pat[selEnd.xCoarse].effectCols*2;
+      selEnd.xFine=2+e->curPat[selEnd.xCoarse].effectCols*2;
     }
   }
 }
@@ -198,9 +199,9 @@ void FurnaceGUI::doDelete() {
   int iCoarse=selStart.xCoarse;
   int iFine=selStart.xFine;
   for (; iCoarse<=selEnd.xCoarse; iCoarse++) {
-    if (!e->song.chanShow[iCoarse]) continue;
-    DivPattern* pat=e->song.pat[iCoarse].getPattern(e->song.orders.ord[iCoarse][curOrder],true);
-    for (; iFine<3+e->song.pat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
+    if (!e->curSubSong->chanShow[iCoarse]) continue;
+    DivPattern* pat=e->curPat[iCoarse].getPattern(e->curOrders->ord[iCoarse][curOrder],true);
+    for (; iFine<3+e->curPat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
       maskOut(opMaskDelete,iFine);
       for (int j=selStart.y; j<=selEnd.y; j++) {
         if (iFine==0) {
@@ -235,12 +236,12 @@ void FurnaceGUI::doPullDelete() {
   int iCoarse=selStart.xCoarse;
   int iFine=selStart.xFine;
   for (; iCoarse<=selEnd.xCoarse; iCoarse++) {
-    if (!e->song.chanShow[iCoarse]) continue;
-    DivPattern* pat=e->song.pat[iCoarse].getPattern(e->song.orders.ord[iCoarse][curOrder],true);
-    for (; iFine<3+e->song.pat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
+    if (!e->curSubSong->chanShow[iCoarse]) continue;
+    DivPattern* pat=e->curPat[iCoarse].getPattern(e->curOrders->ord[iCoarse][curOrder],true);
+    for (; iFine<3+e->curPat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
       maskOut(opMaskPullDelete,iFine);
-      for (int j=selStart.y; j<e->song.patLen; j++) {
-        if (j<e->song.patLen-1) {
+      for (int j=selStart.y; j<e->curSubSong->patLen; j++) {
+        if (j<e->curSubSong->patLen-1) {
           if (iFine==0) {
             pat->data[j][iFine]=pat->data[j+1][iFine];
           }
@@ -267,11 +268,11 @@ void FurnaceGUI::doInsert() {
   int iCoarse=selStart.xCoarse;
   int iFine=selStart.xFine;
   for (; iCoarse<=selEnd.xCoarse; iCoarse++) {
-    if (!e->song.chanShow[iCoarse]) continue;
-    DivPattern* pat=e->song.pat[iCoarse].getPattern(e->song.orders.ord[iCoarse][curOrder],true);
-    for (; iFine<3+e->song.pat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
+    if (!e->curSubSong->chanShow[iCoarse]) continue;
+    DivPattern* pat=e->curPat[iCoarse].getPattern(e->curOrders->ord[iCoarse][curOrder],true);
+    for (; iFine<3+e->curPat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
       maskOut(opMaskInsert,iFine);
-      for (int j=e->song.patLen-1; j>=selStart.y; j--) {
+      for (int j=e->curSubSong->patLen-1; j>=selStart.y; j--) {
         if (j==selStart.y) {
           if (iFine==0) {
             pat->data[j][iFine]=0;
@@ -299,9 +300,9 @@ void FurnaceGUI::doTranspose(int amount, OperationMask& mask) {
   int iCoarse=selStart.xCoarse;
   int iFine=selStart.xFine;
   for (; iCoarse<=selEnd.xCoarse; iCoarse++) {
-    if (!e->song.chanShow[iCoarse]) continue;
-    DivPattern* pat=e->song.pat[iCoarse].getPattern(e->song.orders.ord[iCoarse][curOrder],true);
-    for (; iFine<3+e->song.pat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
+    if (!e->curSubSong->chanShow[iCoarse]) continue;
+    DivPattern* pat=e->curPat[iCoarse].getPattern(e->curOrders->ord[iCoarse][curOrder],true);
+    for (; iFine<3+e->curPat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
       maskOut(mask,iFine);
       for (int j=selStart.y; j<=selEnd.y; j++) {
         if (iFine==0) {
@@ -367,9 +368,9 @@ void FurnaceGUI::doCopy(bool cut) {
     }
     clipboard+='\n';
     for (; iCoarse<=selEnd.xCoarse; iCoarse++) {
-      if (!e->song.chanShow[iCoarse]) continue;
-      DivPattern* pat=e->song.pat[iCoarse].getPattern(e->song.orders.ord[iCoarse][curOrder],true);
-      for (; iFine<3+e->song.pat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
+      if (!e->curSubSong->chanShow[iCoarse]) continue;
+      DivPattern* pat=e->curPat[iCoarse].getPattern(e->curOrders->ord[iCoarse][curOrder],true);
+      for (; iFine<3+e->curPat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
         if (iFine==0) {
           clipboard+=noteNameNormal(pat->data[j][0],pat->data[j][1]);
           if (cut) {
@@ -432,7 +433,7 @@ void FurnaceGUI::doPaste(PasteMode mode) {
 
   int j=cursor.y;
   char note[4];
-  for (size_t i=2; i<data.size() && j<e->song.patLen; i++) {
+  for (size_t i=2; i<data.size() && j<e->curSubSong->patLen; i++) {
     size_t charPos=0;
     int iCoarse=cursor.xCoarse;
     int iFine=(startOff>2 && cursor.xFine>2)?(((cursor.xFine-1)&(~1))|1):startOff;
@@ -440,10 +441,10 @@ void FurnaceGUI::doPaste(PasteMode mode) {
     String& line=data[i];
 
     while (charPos<line.size() && iCoarse<lastChannel) {
-      DivPattern* pat=e->song.pat[iCoarse].getPattern(e->song.orders.ord[iCoarse][curOrder],true);
+      DivPattern* pat=e->curPat[iCoarse].getPattern(e->curOrders->ord[iCoarse][curOrder],true);
       if (line[charPos]=='|') {
         iCoarse++;
-        if (iCoarse<lastChannel) while (!e->song.chanShow[iCoarse]) {
+        if (iCoarse<lastChannel) while (!e->curSubSong->chanShow[iCoarse]) {
           iCoarse++;
           if (iCoarse>=lastChannel) break;
         }
@@ -530,7 +531,7 @@ void FurnaceGUI::doPaste(PasteMode mode) {
             break;
           }
           if (mode!=GUI_PASTE_MODE_MIX_BG || pat->data[j][iFine+1]==-1) {
-            if (iFine<(3+e->song.pat[iCoarse].effectCols*2)) pat->data[j][iFine+1]=val;
+            if (iFine<(3+e->curPat[iCoarse].effectCols*2)) pat->data[j][iFine+1]=val;
           }
         }
       }
@@ -543,7 +544,7 @@ void FurnaceGUI::doPaste(PasteMode mode) {
       break;
     }
     j++;
-    if (mode==GUI_PASTE_MODE_OVERFLOW && j>=e->song.patLen && curOrder<e->song.ordersLen-1) {
+    if (mode==GUI_PASTE_MODE_OVERFLOW && j>=e->curSubSong->patLen && curOrder<e->curSubSong->ordersLen-1) {
       j=0;
       curOrder++;
     }
@@ -554,7 +555,7 @@ void FurnaceGUI::doPaste(PasteMode mode) {
   }
   if (settings.cursorPastePos) {
     cursor.y=j;
-    if (cursor.y>=e->song.patLen) cursor.y=e->song.patLen-1;
+    if (cursor.y>=e->curSubSong->patLen) cursor.y=e->curSubSong->patLen-1;
     updateScroll(cursor.y);
   }
 
@@ -567,8 +568,8 @@ void FurnaceGUI::doChangeIns(int ins) {
 
   int iCoarse=selStart.xCoarse;
   for (; iCoarse<=selEnd.xCoarse; iCoarse++) {
-    if (!e->song.chanShow[iCoarse]) continue;
-    DivPattern* pat=e->song.pat[iCoarse].getPattern(e->song.orders.ord[iCoarse][curOrder],true);
+    if (!e->curSubSong->chanShow[iCoarse]) continue;
+    DivPattern* pat=e->curPat[iCoarse].getPattern(e->curOrders->ord[iCoarse][curOrder],true);
     for (int j=selStart.y; j<=selEnd.y; j++) {
       if (pat->data[j][2]!=-1 || !(pat->data[j][0]==0 && pat->data[j][1]==0)) {
         pat->data[j][2]=ins;
@@ -587,9 +588,9 @@ void FurnaceGUI::doInterpolate() {
   int iCoarse=selStart.xCoarse;
   int iFine=selStart.xFine;
   for (; iCoarse<=selEnd.xCoarse; iCoarse++) {
-    if (!e->song.chanShow[iCoarse]) continue;
-    DivPattern* pat=e->song.pat[iCoarse].getPattern(e->song.orders.ord[iCoarse][curOrder],true);
-    for (; iFine<3+e->song.pat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
+    if (!e->curSubSong->chanShow[iCoarse]) continue;
+    DivPattern* pat=e->curPat[iCoarse].getPattern(e->curOrders->ord[iCoarse][curOrder],true);
+    for (; iFine<3+e->curPat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
       maskOut(opMaskInterpolate,iFine);
       points.clear();
       if (iFine!=0) {
@@ -646,9 +647,9 @@ void FurnaceGUI::doFade(int p0, int p1, bool mode) {
   int iCoarse=selStart.xCoarse;
   int iFine=selStart.xFine;
   for (; iCoarse<=selEnd.xCoarse; iCoarse++) {
-    if (!e->song.chanShow[iCoarse]) continue;
-    DivPattern* pat=e->song.pat[iCoarse].getPattern(e->song.orders.ord[iCoarse][curOrder],true);
-    for (; iFine<3+e->song.pat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
+    if (!e->curSubSong->chanShow[iCoarse]) continue;
+    DivPattern* pat=e->curPat[iCoarse].getPattern(e->curOrders->ord[iCoarse][curOrder],true);
+    for (; iFine<3+e->curPat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
       maskOut(opMaskFade,iFine);
       if (iFine!=0) {
         int absoluteTop=255;
@@ -684,9 +685,9 @@ void FurnaceGUI::doInvertValues() {
   int iCoarse=selStart.xCoarse;
   int iFine=selStart.xFine;
   for (; iCoarse<=selEnd.xCoarse; iCoarse++) {
-    if (!e->song.chanShow[iCoarse]) continue;
-    DivPattern* pat=e->song.pat[iCoarse].getPattern(e->song.orders.ord[iCoarse][curOrder],true);
-    for (; iFine<3+e->song.pat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
+    if (!e->curSubSong->chanShow[iCoarse]) continue;
+    DivPattern* pat=e->curPat[iCoarse].getPattern(e->curOrders->ord[iCoarse][curOrder],true);
+    for (; iFine<3+e->curPat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
       maskOut(opMaskInvertVal,iFine);
       if (iFine!=0) {
         int top=255;
@@ -715,9 +716,9 @@ void FurnaceGUI::doScale(float top) {
   int iCoarse=selStart.xCoarse;
   int iFine=selStart.xFine;
   for (; iCoarse<=selEnd.xCoarse; iCoarse++) {
-    if (!e->song.chanShow[iCoarse]) continue;
-    DivPattern* pat=e->song.pat[iCoarse].getPattern(e->song.orders.ord[iCoarse][curOrder],true);
-    for (; iFine<3+e->song.pat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
+    if (!e->curSubSong->chanShow[iCoarse]) continue;
+    DivPattern* pat=e->curPat[iCoarse].getPattern(e->curOrders->ord[iCoarse][curOrder],true);
+    for (; iFine<3+e->curPat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
       maskOut(opMaskScale,iFine);
       if (iFine!=0) {
         int absoluteTop=255;
@@ -746,9 +747,9 @@ void FurnaceGUI::doRandomize(int bottom, int top, bool mode) {
   int iCoarse=selStart.xCoarse;
   int iFine=selStart.xFine;
   for (; iCoarse<=selEnd.xCoarse; iCoarse++) {
-    if (!e->song.chanShow[iCoarse]) continue;
-    DivPattern* pat=e->song.pat[iCoarse].getPattern(e->song.orders.ord[iCoarse][curOrder],true);
-    for (; iFine<3+e->song.pat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
+    if (!e->curSubSong->chanShow[iCoarse]) continue;
+    DivPattern* pat=e->curPat[iCoarse].getPattern(e->curOrders->ord[iCoarse][curOrder],true);
+    for (; iFine<3+e->curPat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
       maskOut(opMaskRandomize,iFine);
       if (iFine!=0) {
         int absoluteTop=255;
@@ -792,9 +793,9 @@ void FurnaceGUI::doFlip() {
   int iCoarse=selStart.xCoarse;
   int iFine=selStart.xFine;
   for (; iCoarse<=selEnd.xCoarse; iCoarse++) {
-    if (!e->song.chanShow[iCoarse]) continue;
-    DivPattern* pat=e->song.pat[iCoarse].getPattern(e->song.orders.ord[iCoarse][curOrder],true);
-    for (; iFine<3+e->song.pat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
+    if (!e->curSubSong->chanShow[iCoarse]) continue;
+    DivPattern* pat=e->curPat[iCoarse].getPattern(e->curOrders->ord[iCoarse][curOrder],true);
+    for (; iFine<3+e->curPat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
       maskOut(opMaskFlip,iFine);
       for (int j=selStart.y; j<=selEnd.y; j++) {
         if (iFine==0) {
@@ -823,9 +824,9 @@ void FurnaceGUI::doCollapse(int divider) {
   int iCoarse=selStart.xCoarse;
   int iFine=selStart.xFine;
   for (; iCoarse<=selEnd.xCoarse; iCoarse++) {
-    if (!e->song.chanShow[iCoarse]) continue;
-    DivPattern* pat=e->song.pat[iCoarse].getPattern(e->song.orders.ord[iCoarse][curOrder],true);
-    for (; iFine<3+e->song.pat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
+    if (!e->curSubSong->chanShow[iCoarse]) continue;
+    DivPattern* pat=e->curPat[iCoarse].getPattern(e->curOrders->ord[iCoarse][curOrder],true);
+    for (; iFine<3+e->curPat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
       maskOut(opMaskCollapseExpand,iFine);
       for (int j=selStart.y; j<=selEnd.y; j++) {
         if (iFine==0) {
@@ -880,9 +881,9 @@ void FurnaceGUI::doExpand(int multiplier) {
   int iCoarse=selStart.xCoarse;
   int iFine=selStart.xFine;
   for (; iCoarse<=selEnd.xCoarse; iCoarse++) {
-    if (!e->song.chanShow[iCoarse]) continue;
-    DivPattern* pat=e->song.pat[iCoarse].getPattern(e->song.orders.ord[iCoarse][curOrder],true);
-    for (; iFine<3+e->song.pat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
+    if (!e->curSubSong->chanShow[iCoarse]) continue;
+    DivPattern* pat=e->curPat[iCoarse].getPattern(e->curOrders->ord[iCoarse][curOrder],true);
+    for (; iFine<3+e->curPat[iCoarse].effectCols*2 && (iCoarse<selEnd.xCoarse || iFine<=selEnd.xFine); iFine++) {
       maskOut(opMaskCollapseExpand,iFine);
       for (int j=selStart.y; j<=selEnd.y; j++) {
         if (iFine==0) {
@@ -891,7 +892,7 @@ void FurnaceGUI::doExpand(int multiplier) {
         patBuffer.data[j][iFine+1]=pat->data[j][iFine+1];
       }
       for (int j=0; j<=(selEnd.y-selStart.y)*multiplier; j++) {
-        if ((j+selStart.y)>=e->song.patLen) break;
+        if ((j+selStart.y)>=e->curSubSong->patLen) break;
         if ((j%multiplier)!=0) {
           if (iFine==0) {
             pat->data[j+selStart.y][0]=0;
@@ -921,9 +922,10 @@ void FurnaceGUI::doUndo() {
 
   switch (us.type) {
     case GUI_UNDO_CHANGE_ORDER:
-      e->song.ordersLen=us.oldOrdersLen;
+      e->curSubSong->ordersLen=us.oldOrdersLen;
       for (UndoOrderData& i: us.ord) {
-        e->song.orders.ord[i.chan][i.ord]=i.oldVal;
+        e->changeSongP(i.subSong);
+        e->curOrders->ord[i.chan][i.ord]=i.oldVal;
       }
       break;
     case GUI_UNDO_PATTERN_EDIT:
@@ -942,7 +944,8 @@ void FurnaceGUI::doUndo() {
     case GUI_UNDO_PATTERN_COLLAPSE:
     case GUI_UNDO_PATTERN_EXPAND:
       for (UndoPatternData& i: us.pat) {
-        DivPattern* p=e->song.pat[i.chan].getPattern(i.pat,true);
+        e->changeSongP(i.subSong);
+        DivPattern* p=e->curPat[i.chan].getPattern(i.pat,true);
         p->data[i.row][i.col]=i.oldVal;
       }
       if (!e->isPlaying() || !followPattern) {
@@ -967,9 +970,10 @@ void FurnaceGUI::doRedo() {
 
   switch (us.type) {
     case GUI_UNDO_CHANGE_ORDER:
-      e->song.ordersLen=us.newOrdersLen;
+      e->curSubSong->ordersLen=us.newOrdersLen;
       for (UndoOrderData& i: us.ord) {
-        e->song.orders.ord[i.chan][i.ord]=i.newVal;
+        e->changeSongP(i.subSong);
+        e->curOrders->ord[i.chan][i.ord]=i.newVal;
       }
       break;
     case GUI_UNDO_PATTERN_EDIT:
@@ -988,7 +992,8 @@ void FurnaceGUI::doRedo() {
     case GUI_UNDO_PATTERN_COLLAPSE:
     case GUI_UNDO_PATTERN_EXPAND:
       for (UndoPatternData& i: us.pat) {
-        DivPattern* p=e->song.pat[i.chan].getPattern(i.pat,true);
+        e->changeSongP(i.subSong);
+        DivPattern* p=e->curPat[i.chan].getPattern(i.pat,true);
         p->data[i.row][i.col]=i.newVal;
       }
       if (!e->isPlaying()) {
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index 1c52f12bb..ec38c86c2 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -793,9 +793,9 @@ void FurnaceGUI::prepareLayout() {
 }
 
 float FurnaceGUI::calcBPM(int s1, int s2, float hz) {
-  float hl=e->song.hilightA;
+  float hl=e->curSubSong->hilightA;
   if (hl<=0.0f) hl=4.0f;
-  float timeBase=e->song.timeBase+1;
+  float timeBase=e->curSubSong->timeBase+1;
   float speedSum=s1+s2;
   if (timeBase<1.0f) timeBase=1.0f;
   if (speedSum<1.0f) speedSum=1.0f;
@@ -857,7 +857,7 @@ void FurnaceGUI::stopPreviewNote(SDL_Scancode scancode, bool autoNote) {
 }
 
 void FurnaceGUI::noteInput(int num, int key, int vol) {
-  DivPattern* pat=e->song.pat[cursor.xCoarse].getPattern(e->song.orders.ord[cursor.xCoarse][curOrder],true);
+  DivPattern* pat=e->curPat[cursor.xCoarse].getPattern(e->curOrders->ord[cursor.xCoarse][curOrder],true);
   
   prepareUndo(GUI_UNDO_PATTERN_EDIT);
 
@@ -901,7 +901,7 @@ void FurnaceGUI::noteInput(int num, int key, int vol) {
 }
 
 void FurnaceGUI::valueInput(int num, bool direct, int target) {
-  DivPattern* pat=e->song.pat[cursor.xCoarse].getPattern(e->song.orders.ord[cursor.xCoarse][curOrder],true);
+  DivPattern* pat=e->curPat[cursor.xCoarse].getPattern(e->curOrders->ord[cursor.xCoarse][curOrder],true);
   prepareUndo(GUI_UNDO_PATTERN_EDIT);
   if (target==-1) target=cursor.xFine+1;
   if (direct) {
@@ -965,7 +965,7 @@ void FurnaceGUI::valueInput(int num, bool direct, int target) {
           editAdvance();
         } else {
           if (settings.effectCursorDir==2) {
-            if (++cursor.xFine>=(3+(e->song.pat[cursor.xCoarse].effectCols*2))) {
+            if (++cursor.xFine>=(3+(e->curPat[cursor.xCoarse].effectCols*2))) {
               cursor.xFine=3;
             }
           } else {
@@ -1123,7 +1123,7 @@ void FurnaceGUI::keyDown(SDL_Event& ev) {
           int num=valueKeys.at(ev.key.keysym.sym);
           if (orderCursor>=0 && orderCursor<e->getTotalChannelCount()) {
             e->lockSave([this,num]() {
-              e->song.orders.ord[orderCursor][curOrder]=((e->song.orders.ord[orderCursor][curOrder]<<4)|num);
+              e->curOrders->ord[orderCursor][curOrder]=((e->curOrders->ord[orderCursor][curOrder]<<4)|num);
             });
             if (orderEditMode==2 || orderEditMode==3) {
               curNibble=!curNibble;
@@ -1132,7 +1132,7 @@ void FurnaceGUI::keyDown(SDL_Event& ev) {
                   orderCursor++;
                   if (orderCursor>=e->getTotalChannelCount()) orderCursor=0;
                 } else if (orderEditMode==3) {
-                  if (curOrder<e->song.ordersLen-1) {
+                  if (curOrder<e->curSubSong->ordersLen-1) {
                     setOrder(curOrder+1);
                   }
                 }
@@ -2047,7 +2047,7 @@ void FurnaceGUI::editOptions(bool topMenu) {
   ImGui::PopFont();
   ImGui::SameLine();
   if (ImGui::Button("Set")) {
-    DivPattern* pat=e->song.pat[cursor.xCoarse].getPattern(e->song.orders.ord[cursor.xCoarse][curOrder],true);
+    DivPattern* pat=e->curPat[cursor.xCoarse].getPattern(e->curOrders->ord[cursor.xCoarse][curOrder],true);
     latchIns=pat->data[cursor.y][2];
     latchVol=pat->data[cursor.y][3];
     latchEffect=pat->data[cursor.y][4];
@@ -2833,12 +2833,12 @@ bool FurnaceGUI::loop() {
     if (e->isPlaying()) {
       int totalTicks=e->getTotalTicks();
       int totalSeconds=e->getTotalSeconds();
-      ImGui::Text("| Speed %d:%d @ %gHz (%g BPM) | Order %d/%d | Row %d/%d | %d:%.2d:%.2d.%.2d",e->getSpeed1(),e->getSpeed2(),e->getCurHz(),calcBPM(e->getSpeed1(),e->getSpeed2(),e->getCurHz()),e->getOrder(),e->song.ordersLen,e->getRow(),e->song.patLen,totalSeconds/3600,(totalSeconds/60)%60,totalSeconds%60,totalTicks/10000);
+      ImGui::Text("| Speed %d:%d @ %gHz (%g BPM) | Order %d/%d | Row %d/%d | %d:%.2d:%.2d.%.2d",e->getSpeed1(),e->getSpeed2(),e->getCurHz(),calcBPM(e->getSpeed1(),e->getSpeed2(),e->getCurHz()),e->getOrder(),e->curSubSong->ordersLen,e->getRow(),e->curSubSong->patLen,totalSeconds/3600,(totalSeconds/60)%60,totalSeconds%60,totalTicks/10000);
     } else {
       bool hasInfo=false;
       String info;
       if (cursor.xCoarse>=0 && cursor.xCoarse<e->getTotalChannelCount()) {
-        DivPattern* p=e->song.pat[cursor.xCoarse].getPattern(e->song.orders.ord[cursor.xCoarse][curOrder],false);
+        DivPattern* p=e->curPat[cursor.xCoarse].getPattern(e->curOrders->ord[cursor.xCoarse][curOrder],false);
         if (cursor.xFine>=0) switch (cursor.xFine) {
           case 0: // note
             if (p->data[cursor.y][0]>0) {
@@ -2899,6 +2899,7 @@ bool FurnaceGUI::loop() {
 
     ImGui::DockSpaceOverViewport(NULL,lockLayout?(ImGuiDockNodeFlags_NoResize|ImGuiDockNodeFlags_NoCloseButton|ImGuiDockNodeFlags_NoDocking|ImGuiDockNodeFlags_NoDockingSplitMe|ImGuiDockNodeFlags_NoDockingSplitOther):0);
 
+    drawSubSongs();
     drawPattern();
     drawEditControls();
     drawSongInfo();
@@ -3177,8 +3178,11 @@ bool FurnaceGUI::loop() {
               break;
             }
             case GUI_FILE_WAVE_OPEN:
-              e->addWaveFromFile(copyOfName.c_str());
-              MARK_MODIFIED;
+              if (!e->addWaveFromFile(copyOfName.c_str())) {
+                showError("cannot load wavetable! ("+e->getLastError()+")");
+              } else {
+                MARK_MODIFIED;
+              }
               break;
             case GUI_FILE_EXPORT_VGM: {
               SafeWriter* w=e->saveVGM(willExport,vgmExportLoop,vgmExportVersion);
@@ -3504,7 +3508,7 @@ bool FurnaceGUI::loop() {
             stop();
             e->lockEngine([this]() {
               for (int i=0; i<e->getTotalChannelCount(); i++) {
-                DivPattern* pat=e->song.pat[i].getPattern(e->song.orders.ord[i][curOrder],true);
+                DivPattern* pat=e->curPat[i].getPattern(e->curOrders->ord[i][curOrder],true);
                 memset(pat->data,-1,256*32*sizeof(short));
                 for (int j=0; j<256; j++) {
                   pat->data[j][0]=0;
@@ -3663,6 +3667,7 @@ bool FurnaceGUI::init() {
   regViewOpen=e->getConfBool("regViewOpen",false);
   logOpen=e->getConfBool("logOpen",false);
   effectListOpen=e->getConfBool("effectListOpen",false);
+  subSongsOpen=e->getConfBool("subSongsOpen",true);
 
   tempoView=e->getConfBool("tempoView",true);
   waveHex=e->getConfBool("waveHex",false);
@@ -3854,6 +3859,7 @@ bool FurnaceGUI::finish() {
   e->setConf("regViewOpen",regViewOpen);
   e->setConf("logOpen",logOpen);
   e->setConf("effectListOpen",effectListOpen);
+  e->setConf("subSongsOpen",subSongsOpen);
 
   // commit last window size
   e->setConf("lastWindowWidth",scrW);
@@ -3974,6 +3980,7 @@ FurnaceGUI::FurnaceGUI():
   logOpen(false),
   effectListOpen(false),
   chanOscOpen(false),
+  subSongsOpen(true),
   /*
   editControlsDocked(false),
   ordersDocked(false),
@@ -4001,6 +4008,7 @@ FurnaceGUI::FurnaceGUI():
   logDocked(false),
   effectListDocked(false),
   chanOscDocked(false),
+  subSongsDocked(false),
   */
   selecting(false),
   selectingFull(false),
diff --git a/src/gui/gui.h b/src/gui/gui.h
index 4a5045129..b976a7cb7 100644
--- a/src/gui/gui.h
+++ b/src/gui/gui.h
@@ -231,7 +231,8 @@ enum FurnaceGUIWindows {
   GUI_WINDOW_REGISTER_VIEW,
   GUI_WINDOW_LOG,
   GUI_WINDOW_EFFECT_LIST,
-  GUI_WINDOW_CHAN_OSC
+  GUI_WINDOW_CHAN_OSC,
+  GUI_WINDOW_SUBSONGS
 };
 
 enum FurnaceGUIFileDialogs {
@@ -337,6 +338,7 @@ enum FurnaceGUIActions {
   GUI_ACTION_WINDOW_LOG,
   GUI_ACTION_WINDOW_EFFECT_LIST,
   GUI_ACTION_WINDOW_CHAN_OSC,
+  GUI_ACTION_WINDOW_SUBSONGS,
 
   GUI_ACTION_COLLAPSE_WINDOW,
   GUI_ACTION_CLOSE_WINDOW,
@@ -550,9 +552,10 @@ enum ActionType {
 };
 
 struct UndoPatternData {
-  int chan, pat, row, col;
+  int subSong, chan, pat, row, col;
   short oldVal, newVal;
-  UndoPatternData(int c, int p, int r, int co, short v1, short v2):
+  UndoPatternData(int s, int c, int p, int r, int co, short v1, short v2):
+    subSong(s),
     chan(c),
     pat(p),
     row(r),
@@ -562,9 +565,10 @@ struct UndoPatternData {
 };
 
 struct UndoOrderData {
-  int chan, ord;
+  int subSong, chan, ord;
   unsigned char oldVal, newVal;
-  UndoOrderData(int c, int o, unsigned char v1, unsigned char v2):
+  UndoOrderData(int s, int c, int o, unsigned char v1, unsigned char v2):
+    subSong(s),
     chan(c),
     ord(o),
     oldVal(v1),
@@ -1010,12 +1014,14 @@ class FurnaceGUI {
   bool waveListOpen, waveEditOpen, sampleListOpen, sampleEditOpen, aboutOpen, settingsOpen;
   bool mixerOpen, debugOpen, inspectorOpen, oscOpen, volMeterOpen, statsOpen, compatFlagsOpen;
   bool pianoOpen, notesOpen, channelsOpen, regViewOpen, logOpen, effectListOpen, chanOscOpen;
+  bool subSongsOpen;
 
   /* there ought to be a better way...
   bool editControlsDocked, ordersDocked, insListDocked, songInfoDocked, patternDocked, insEditDocked;
   bool waveListDocked, waveEditDocked, sampleListDocked, sampleEditDocked, aboutDocked, settingsDocked;
   bool mixerDocked, debugDocked, inspectorDocked, oscDocked, volMeterDocked, statsDocked, compatFlagsDocked;
   bool pianoDocked, notesDocked, channelsDocked, regViewDocked, logDocked, effectListDocked, chanOscDocked;
+  bool subSongsDocked;
   */
 
   SelectionPoint selStart, selEnd, cursor;
@@ -1246,6 +1252,7 @@ class FurnaceGUI {
   void drawNewSong();
   void drawLog();
   void drawEffectList();
+  void drawSubSongs();
 
   void parseKeybinds();
   void promptKey(int which);
diff --git a/src/gui/guiConst.cpp b/src/gui/guiConst.cpp
index a02543aa5..31aad6432 100644
--- a/src/gui/guiConst.cpp
+++ b/src/gui/guiConst.cpp
@@ -116,8 +116,8 @@ const char* insTypes[DIV_INS_MAX]={
 const char* sampleDepths[17]={
   "1-bit PCM",
   "1-bit DPCM",
-  NULL,
-  NULL,
+  "Yamaha AICA",
+  "YMZ/YMU ADPCM",
   "QSound ADPCM",
   "ADPCM-A",
   "ADPCM-B",
@@ -485,6 +485,7 @@ const FurnaceGUIActionDef guiActions[GUI_ACTION_MAX]={
   D("WINDOW_CHANNELS", "Channels", 0),
   D("WINDOW_REGISTER_VIEW", "Register View", 0),
   D("WINDOW_LOG", "Log Viewer", 0),
+  D("WINDOW_SUBSONGS", "Subsongs", 0),
   D("EFFECT_LIST", "Effect List", 0),
   D("WINDOW_CHAN_OSC", "Oscilloscope (per-channel)", 0),
 
diff --git a/src/gui/orders.cpp b/src/gui/orders.cpp
index 2311a3980..e9886a1ae 100644
--- a/src/gui/orders.cpp
+++ b/src/gui/orders.cpp
@@ -37,7 +37,7 @@ void FurnaceGUI::drawOrders() {
     ImGui::SetColumnWidth(-1,regionX-24.0f*dpiScale);
     int displayChans=0;
     for (int i=0; i<e->getTotalChannelCount(); i++) {
-      if (e->song.chanShow[i]) displayChans++;
+      if (e->curSubSong->chanShow[i]) displayChans++;
     }
     ImGui::PushFont(patFont);
     bool tooSmall=((displayChans+1)>((ImGui::GetContentRegionAvail().x)/(ImGui::CalcTextSize("AA").x+2.0*ImGui::GetStyle().ItemInnerSpacing.x)));
@@ -56,12 +56,12 @@ void FurnaceGUI::drawOrders() {
       ImGui::TableNextColumn();
       ImGui::PushStyleColor(ImGuiCol_Text,uiColors[GUI_COLOR_ORDER_ROW_INDEX]);
       for (int i=0; i<e->getTotalChannelCount(); i++) {
-        if (!e->song.chanShow[i]) continue;
+        if (!e->curSubSong->chanShow[i]) continue;
         ImGui::TableNextColumn();
         ImGui::Text("%s",e->getChannelShortName(i));
       }
       ImGui::PopStyleColor();
-      for (int i=0; i<e->song.ordersLen; i++) {
+      for (int i=0; i<e->curSubSong->ordersLen; i++) {
         ImGui::TableNextRow(0,lineHeight);
         if (oldOrder1==i) ImGui::TableSetBgColor(ImGuiTableBgTarget_RowBg0,ImGui::GetColorU32(uiColors[GUI_COLOR_ORDER_ACTIVE]));
         ImGui::TableNextColumn();
@@ -84,16 +84,16 @@ void FurnaceGUI::drawOrders() {
         }
         ImGui::PopStyleColor();
         for (int j=0; j<e->getTotalChannelCount(); j++) {
-          if (!e->song.chanShow[j]) continue;
+          if (!e->curSubSong->chanShow[j]) continue;
           ImGui::TableNextColumn();
-          DivPattern* pat=e->song.pat[j].getPattern(e->song.orders.ord[j][i],false);
+          DivPattern* pat=e->curPat[j].getPattern(e->curOrders->ord[j][i],false);
           /*if (!pat->name.empty()) {
             snprintf(selID,4096,"%s##O_%.2x_%.2x",pat->name.c_str(),j,i);
           } else {*/
-            snprintf(selID,4096,"%.2X##O_%.2x_%.2x",e->song.orders.ord[j][i],j,i);
+            snprintf(selID,4096,"%.2X##O_%.2x_%.2x",e->curOrders->ord[j][i],j,i);
           //}
 
-          ImGui::PushStyleColor(ImGuiCol_Text,(curOrder==i || e->song.orders.ord[j][i]==e->song.orders.ord[j][curOrder])?uiColors[GUI_COLOR_ORDER_SIMILAR]:uiColors[GUI_COLOR_ORDER_INACTIVE]);
+          ImGui::PushStyleColor(ImGuiCol_Text,(curOrder==i || e->curOrders->ord[j][i]==e->curOrders->ord[j][curOrder])?uiColors[GUI_COLOR_ORDER_SIMILAR]:uiColors[GUI_COLOR_ORDER_INACTIVE]);
           if (ImGui::Selectable(selID,(orderEditMode!=0 && curOrder==i && orderCursor==j))) {
             if (curOrder==i) {
               if (orderEditMode==0) {
@@ -101,10 +101,10 @@ void FurnaceGUI::drawOrders() {
                 e->lockSave([this,i,j]() {
                   if (changeAllOrders) {
                     for (int k=0; k<e->getTotalChannelCount(); k++) {
-                      if (e->song.orders.ord[k][i]<0xff) e->song.orders.ord[k][i]++;
+                      if (e->curOrders->ord[k][i]<0xff) e->curOrders->ord[k][i]++;
                     }
                   } else {
-                    if (e->song.orders.ord[j][i]<0xff) e->song.orders.ord[j][i]++;
+                    if (e->curOrders->ord[j][i]<0xff) e->curOrders->ord[j][i]++;
                   }
                 });
                 e->walkSong(loopOrder,loopRow,loopEnd);
@@ -137,10 +137,10 @@ void FurnaceGUI::drawOrders() {
                 e->lockSave([this,i,j]() {
                   if (changeAllOrders) {
                     for (int k=0; k<e->getTotalChannelCount(); k++) {
-                      if (e->song.orders.ord[k][i]>0) e->song.orders.ord[k][i]--;
+                      if (e->curOrders->ord[k][i]>0) e->curOrders->ord[k][i]--;
                     }
                   } else {
-                    if (e->song.orders.ord[j][i]>0) e->song.orders.ord[j][i]--;
+                    if (e->curOrders->ord[j][i]>0) e->curOrders->ord[j][i]--;
                   }
                 });
                 e->walkSong(loopOrder,loopRow,loopEnd);
diff --git a/src/gui/pattern.cpp b/src/gui/pattern.cpp
index ae9bedb2c..b7ca4bed9 100644
--- a/src/gui/pattern.cpp
+++ b/src/gui/pattern.cpp
@@ -43,21 +43,21 @@ inline void FurnaceGUI::patternRow(int i, bool isPlaying, float lineHeight, int
     return;
   }
   // check if we are in range
-  if (ord<0 || ord>=e->song.ordersLen) {
+  if (ord<0 || ord>=e->curSubSong->ordersLen) {
     return;
   }
-  if (i<0 || i>=e->song.patLen) {
+  if (i<0 || i>=e->curSubSong->patLen) {
     return;
   }
   bool isPushing=false;
   ImVec4 activeColor=uiColors[GUI_COLOR_PATTERN_ACTIVE];
   ImVec4 inactiveColor=uiColors[GUI_COLOR_PATTERN_INACTIVE];
   ImVec4 rowIndexColor=uiColors[GUI_COLOR_PATTERN_ROW_INDEX];
-  if (e->song.hilightB>0 && !(i%e->song.hilightB)) {
+  if (e->curSubSong->hilightB>0 && !(i%e->curSubSong->hilightB)) {
     activeColor=uiColors[GUI_COLOR_PATTERN_ACTIVE_HI2];
     inactiveColor=uiColors[GUI_COLOR_PATTERN_INACTIVE_HI2];
     rowIndexColor=uiColors[GUI_COLOR_PATTERN_ROW_INDEX_HI2];
-  } else if (e->song.hilightA>0 && !(i%e->song.hilightA)) {
+  } else if (e->curSubSong->hilightA>0 && !(i%e->curSubSong->hilightA)) {
     activeColor=uiColors[GUI_COLOR_PATTERN_ACTIVE_HI1];
     inactiveColor=uiColors[GUI_COLOR_PATTERN_INACTIVE_HI1];
     rowIndexColor=uiColors[GUI_COLOR_PATTERN_ROW_INDEX_HI1];
@@ -68,9 +68,9 @@ inline void FurnaceGUI::patternRow(int i, bool isPlaying, float lineHeight, int
       ImGui::TableSetBgColor(ImGuiTableBgTarget_RowBg0,ImGui::GetColorU32(uiColors[GUI_COLOR_EDITING]));
     } else if (isPlaying && oldRow==i && ord==e->getOrder()) {
       ImGui::TableSetBgColor(ImGuiTableBgTarget_RowBg0,ImGui::GetColorU32(uiColors[GUI_COLOR_PATTERN_PLAY_HEAD]));
-    } else if (e->song.hilightB>0 && !(i%e->song.hilightB)) {
+    } else if (e->curSubSong->hilightB>0 && !(i%e->curSubSong->hilightB)) {
       ImGui::TableSetBgColor(ImGuiTableBgTarget_RowBg0,ImGui::GetColorU32(uiColors[GUI_COLOR_PATTERN_HI_2]));
-    } else if (e->song.hilightA>0 && !(i%e->song.hilightA)) {
+    } else if (e->curSubSong->hilightA>0 && !(i%e->curSubSong->hilightA)) {
       ImGui::TableSetBgColor(ImGuiTableBgTarget_RowBg0,ImGui::GetColorU32(uiColors[GUI_COLOR_PATTERN_HI_1]));
     }
   } else {
@@ -79,9 +79,9 @@ inline void FurnaceGUI::patternRow(int i, bool isPlaying, float lineHeight, int
       ImGui::PushStyleColor(ImGuiCol_Header,ImGui::GetColorU32(uiColors[GUI_COLOR_EDITING]));
     } else if (isPlaying && oldRow==i && ord==e->getOrder()) {
       ImGui::PushStyleColor(ImGuiCol_Header,ImGui::GetColorU32(uiColors[GUI_COLOR_PATTERN_PLAY_HEAD]));
-    } else if (e->song.hilightB>0 && !(i%e->song.hilightB)) {
+    } else if (e->curSubSong->hilightB>0 && !(i%e->curSubSong->hilightB)) {
       ImGui::PushStyleColor(ImGuiCol_Header,ImGui::GetColorU32(uiColors[GUI_COLOR_PATTERN_HI_2]));
-    } else if (e->song.hilightA>0 && !(i%e->song.hilightA)) {
+    } else if (e->curSubSong->hilightA>0 && !(i%e->curSubSong->hilightA)) {
       ImGui::PushStyleColor(ImGuiCol_Header,ImGui::GetColorU32(uiColors[GUI_COLOR_PATTERN_HI_1]));
     } else {
       isPushing=false;
@@ -106,7 +106,7 @@ inline void FurnaceGUI::patternRow(int i, bool isPlaying, float lineHeight, int
   // for each column
   for (int j=0; j<chans; j++) {
     // check if channel is not hidden
-    if (!e->song.chanShow[j]) {
+    if (!e->curSubSong->chanShow[j]) {
       patChanX[j]=ImGui::GetCursorPosX();
       continue;
     }
@@ -155,7 +155,7 @@ inline void FurnaceGUI::patternRow(int i, bool isPlaying, float lineHeight, int
     ImGui::PopStyleColor();
 
     // the following is only visible when the channel is not collapsed
-    if (e->song.chanCollapse[j]<3) {
+    if (e->curSubSong->chanCollapse[j]<3) {
       // instrument
       if (pat->data[i][2]==-1) {
         ImGui::PushStyleColor(ImGuiCol_Text,inactiveColor);
@@ -195,7 +195,7 @@ inline void FurnaceGUI::patternRow(int i, bool isPlaying, float lineHeight, int
       ImGui::PopStyleColor();
     }
 
-    if (e->song.chanCollapse[j]<2) {
+    if (e->curSubSong->chanCollapse[j]<2) {
       // volume
       if (pat->data[i][3]==-1) {
         sprintf(id,"..##PV_%d_%d",i,j);
@@ -229,9 +229,9 @@ inline void FurnaceGUI::patternRow(int i, bool isPlaying, float lineHeight, int
       ImGui::PopStyleColor();
     }
 
-    if (e->song.chanCollapse[j]<1) {
+    if (e->curSubSong->chanCollapse[j]<1) {
       // effects
-      for (int k=0; k<e->song.pat[j].effectCols; k++) {
+      for (int k=0; k<e->curPat[j].effectCols; k++) {
         int index=4+(k<<1);
         bool selectedEffect=selectedRow && (j32+index-1>=sel1XSum && j32+index-1<=sel2XSum);
         bool selectedEffectVal=selectedRow && (j32+index>=sel1XSum && j32+index<=sel2XSum);
@@ -358,7 +358,7 @@ void FurnaceGUI::drawPattern() {
     int displayChans=0;
     const DivPattern* patCache[DIV_MAX_CHANS];
     for (int i=0; i<chans; i++) {
-      if (e->song.chanShow[i]) displayChans++;
+      if (e->curSubSong->chanShow[i]) displayChans++;
     }
     ImGui::PushStyleVar(ImGuiStyleVar_CellPadding,ImVec2(0.0f,0.0f));
     ImGui::PushStyleColor(ImGuiCol_Header,uiColors[GUI_COLOR_PATTERN_SELECTION]);
@@ -383,7 +383,7 @@ void FurnaceGUI::drawPattern() {
       }
       ImGui::TableSetupScrollFreeze(1,1);
       for (int i=0; i<chans; i++) {
-        if (!e->song.chanShow[i]) continue;
+        if (!e->curSubSong->chanShow[i]) continue;
         ImGui::TableSetupColumn(fmt::sprintf("c%d",i).c_str(),ImGuiTableColumnFlags_WidthFixed);
       }
       ImGui::TableNextRow();
@@ -408,10 +408,10 @@ void FurnaceGUI::drawPattern() {
         cmdStream.clear();
       }
       for (int i=0; i<chans; i++) {
-        if (!e->song.chanShow[i]) continue;
+        if (!e->curSubSong->chanShow[i]) continue;
         ImGui::TableNextColumn();
         bool displayTooltip=false;
-        if (e->song.chanCollapse[i]) {
+        if (e->curSubSong->chanCollapse[i]) {
           const char* chName=e->getChannelShortName(i);
           if (strlen(chName)>3) {
             snprintf(chanID,2048,"...##_CH%d",i);
@@ -421,7 +421,7 @@ void FurnaceGUI::drawPattern() {
           displayTooltip=true;
         } else {
           const char* chName=e->getChannelName(i);
-          size_t chNameLimit=6+4*e->song.pat[i].effectCols;
+          size_t chNameLimit=6+4*e->curPat[i].effectCols;
           if (strlen(chName)>chNameLimit) {
             String shortChName=chName;
             shortChName.resize(chNameLimit-3);
@@ -483,7 +483,7 @@ void FurnaceGUI::drawPattern() {
           e->toggleSolo(i);
         }
         if (extraChannelButtons==2) {
-          DivPattern* pat=e->song.pat[i].getPattern(e->song.orders.ord[i][ord],true);
+          DivPattern* pat=e->curPat[i].getPattern(e->curOrders->ord[i][ord],true);
           ImGui::PushFont(mainFont);
           if (patNameTarget==i) {
             snprintf(chanID,2048,"##PatNameI%d_%d",i,ord);
@@ -510,30 +510,30 @@ void FurnaceGUI::drawPattern() {
           }
           ImGui::PopFont();
         } else if (extraChannelButtons==1) {
-          snprintf(chanID,2048,"%c##_HCH%d",e->song.chanCollapse[i]?'+':'-',i);
+          snprintf(chanID,2048,"%c##_HCH%d",e->curSubSong->chanCollapse[i]?'+':'-',i);
           ImGui::SetCursorPosX(ImGui::GetCursorPosX()+4.0f*dpiScale);
           if (ImGui::SmallButton(chanID)) {
-            if (e->song.chanCollapse[i]==0) {
-              e->song.chanCollapse[i]=3;
-            } else if (e->song.chanCollapse[i]>0) {
-              e->song.chanCollapse[i]--;
+            if (e->curSubSong->chanCollapse[i]==0) {
+              e->curSubSong->chanCollapse[i]=3;
+            } else if (e->curSubSong->chanCollapse[i]>0) {
+              e->curSubSong->chanCollapse[i]--;
             }
           }
-          if (!e->song.chanCollapse[i]) {
+          if (!e->curSubSong->chanCollapse[i]) {
             ImGui::SameLine();
             snprintf(chanID,2048,"<##_LCH%d",i);
-            ImGui::BeginDisabled(e->song.pat[i].effectCols<=1);
+            ImGui::BeginDisabled(e->curPat[i].effectCols<=1);
             if (ImGui::SmallButton(chanID)) {
-              e->song.pat[i].effectCols--;
-              if (e->song.pat[i].effectCols<1) e->song.pat[i].effectCols=1;
+              e->curPat[i].effectCols--;
+              if (e->curPat[i].effectCols<1) e->curPat[i].effectCols=1;
             }
             ImGui::EndDisabled();
             ImGui::SameLine();
-            ImGui::BeginDisabled(e->song.pat[i].effectCols>=8);
+            ImGui::BeginDisabled(e->curPat[i].effectCols>=8);
             snprintf(chanID,2048,">##_RCH%d",i);
             if (ImGui::SmallButton(chanID)) {
-              e->song.pat[i].effectCols++;
-              if (e->song.pat[i].effectCols>8) e->song.pat[i].effectCols=8;
+              e->curPat[i].effectCols++;
+              if (e->curPat[i].effectCols>8) e->curPat[i].effectCols=8;
             }
             ImGui::EndDisabled();
           }
@@ -555,10 +555,10 @@ void FurnaceGUI::drawPattern() {
       ImGui::BeginDisabled();
       if (settings.viewPrevPattern) {
         if ((ord-1)>=0) for (int i=0; i<chans; i++) {
-          patCache[i]=e->song.pat[i].getPattern(e->song.orders.ord[i][ord-1],true);
+          patCache[i]=e->curPat[i].getPattern(e->curOrders->ord[i][ord-1],true);
         }
         for (int i=0; i<dummyRows-1; i++) {
-          patternRow(e->song.patLen+i-dummyRows+1,e->isPlaying(),lineHeight,chans,ord-1,patCache,true);
+          patternRow(e->curSubSong->patLen+i-dummyRows+1,e->isPlaying(),lineHeight,chans,ord-1,patCache,true);
         }
       } else {
         for (int i=0; i<dummyRows-1; i++) {
@@ -569,16 +569,16 @@ void FurnaceGUI::drawPattern() {
       ImGui::EndDisabled();
       // active area
       for (int i=0; i<chans; i++) {
-        patCache[i]=e->song.pat[i].getPattern(e->song.orders.ord[i][ord],true);
+        patCache[i]=e->curPat[i].getPattern(e->curOrders->ord[i][ord],true);
       }
-      for (int i=0; i<e->song.patLen; i++) {
+      for (int i=0; i<e->curSubSong->patLen; i++) {
         patternRow(i,e->isPlaying(),lineHeight,chans,ord,patCache,false);
       }
       // next pattern
       ImGui::BeginDisabled();
       if (settings.viewPrevPattern) {
-        if ((ord+1)<e->song.ordersLen) for (int i=0; i<chans; i++) {
-          patCache[i]=e->song.pat[i].getPattern(e->song.orders.ord[i][ord+1],true);
+        if ((ord+1)<e->curSubSong->ordersLen) for (int i=0; i<chans; i++) {
+          patCache[i]=e->curPat[i].getPattern(e->curOrders->ord[i][ord+1],true);
         }
         for (int i=0; i<=dummyRows; i++) {
           patternRow(i,e->isPlaying(),lineHeight,chans,ord+1,patCache,true);
@@ -612,7 +612,7 @@ void FurnaceGUI::drawPattern() {
                 if (curOrder>0) {
                   setOrder(curOrder-1);
                   ImGui::SetScrollY(ImGui::GetScrollMaxY());
-                  updateScroll(e->song.patLen);
+                  updateScroll(e->curSubSong->patLen);
                 }
                 haveHitBounds=false;
               } else {
@@ -624,7 +624,7 @@ void FurnaceGUI::drawPattern() {
           } else {
             if (ImGui::GetScrollY()>=ImGui::GetScrollMaxY()) {
               if (haveHitBounds) {
-                if (curOrder<(e->song.ordersLen-1)) {
+                if (curOrder<(e->curSubSong->ordersLen-1)) {
                   setOrder(curOrder+1);
                   ImGui::SetScrollY(0);
                   updateScroll(0);
@@ -776,7 +776,7 @@ void FurnaceGUI::drawPattern() {
       // note slides
       ImVec2 arrowPoints[7];
       if (e->isPlaying()) for (int i=0; i<chans; i++) {
-        if (!e->song.chanShow[i]) continue;
+        if (!e->curSubSong->chanShow[i]) continue;
         DivChannelState* ch=e->getChanState(i);
         if (ch->portaSpeed>0) {
           ImVec4 col=uiColors[GUI_COLOR_PATTERN_EFFECT_PITCH];
diff --git a/src/gui/settings.cpp b/src/gui/settings.cpp
index 741705aee..6a99d84c9 100644
--- a/src/gui/settings.cpp
+++ b/src/gui/settings.cpp
@@ -1495,6 +1495,7 @@ void FurnaceGUI::drawSettings() {
             UI_KEYBIND_CONFIG(GUI_ACTION_WINDOW_INS_LIST);
             UI_KEYBIND_CONFIG(GUI_ACTION_WINDOW_INS_EDIT);
             UI_KEYBIND_CONFIG(GUI_ACTION_WINDOW_SONG_INFO);
+            UI_KEYBIND_CONFIG(GUI_ACTION_WINDOW_SUBSONGS);
             UI_KEYBIND_CONFIG(GUI_ACTION_WINDOW_PATTERN);
             UI_KEYBIND_CONFIG(GUI_ACTION_WINDOW_WAVE_LIST);
             UI_KEYBIND_CONFIG(GUI_ACTION_WINDOW_WAVE_EDIT);
diff --git a/src/gui/songInfo.cpp b/src/gui/songInfo.cpp
index 552f1c5d3..d62abef85 100644
--- a/src/gui/songInfo.cpp
+++ b/src/gui/songInfo.cpp
@@ -18,6 +18,7 @@
  */
 
 #include "gui.h"
+#include "imgui.h"
 #include "misc/cpp/imgui_stdlib.h"
 #include "intConst.h"
 
@@ -74,28 +75,28 @@ void FurnaceGUI::drawSongInfo() {
       ImGui::TableNextColumn();
       float avail=ImGui::GetContentRegionAvail().x;
       ImGui::SetNextItemWidth(avail);
-      unsigned char realTB=e->song.timeBase+1;
+      unsigned char realTB=e->curSubSong->timeBase+1;
       if (ImGui::InputScalar("##TimeBase",ImGuiDataType_U8,&realTB,&_ONE,&_THREE)) { MARK_MODIFIED
         if (realTB<1) realTB=1;
         if (realTB>16) realTB=16;
-        e->song.timeBase=realTB-1;
+        e->curSubSong->timeBase=realTB-1;
       }
       ImGui::TableNextColumn();
-      ImGui::Text("%.2f BPM",calcBPM(e->song.speed1,e->song.speed2,e->song.hz));
+      ImGui::Text("%.2f BPM",calcBPM(e->curSubSong->speed1,e->curSubSong->speed2,e->curSubSong->hz));
 
       ImGui::TableNextRow();
       ImGui::TableNextColumn();
       ImGui::Text("Speed");
       ImGui::TableNextColumn();
       ImGui::SetNextItemWidth(avail);
-      if (ImGui::InputScalar("##Speed1",ImGuiDataType_U8,&e->song.speed1,&_ONE,&_THREE)) { MARK_MODIFIED
-        if (e->song.speed1<1) e->song.speed1=1;
+      if (ImGui::InputScalar("##Speed1",ImGuiDataType_U8,&e->curSubSong->speed1,&_ONE,&_THREE)) { MARK_MODIFIED
+        if (e->curSubSong->speed1<1) e->curSubSong->speed1=1;
         if (e->isPlaying()) play();
       }
       ImGui::TableNextColumn();
       ImGui::SetNextItemWidth(avail);
-      if (ImGui::InputScalar("##Speed2",ImGuiDataType_U8,&e->song.speed2,&_ONE,&_THREE)) { MARK_MODIFIED
-        if (e->song.speed2<1) e->song.speed2=1;
+      if (ImGui::InputScalar("##Speed2",ImGuiDataType_U8,&e->curSubSong->speed2,&_ONE,&_THREE)) { MARK_MODIFIED
+        if (e->curSubSong->speed2<1) e->curSubSong->speed2=1;
         if (e->isPlaying()) play();
       }
 
@@ -104,12 +105,12 @@ void FurnaceGUI::drawSongInfo() {
       ImGui::Text("Highlight");
       ImGui::TableNextColumn();
       ImGui::SetNextItemWidth(avail);
-      if (ImGui::InputScalar("##Highlight1",ImGuiDataType_U8,&e->song.hilightA,&_ONE,&_THREE)) {
+      if (ImGui::InputScalar("##Highlight1",ImGuiDataType_U8,&e->curSubSong->hilightA,&_ONE,&_THREE)) {
         MARK_MODIFIED;
       }
       ImGui::TableNextColumn();
       ImGui::SetNextItemWidth(avail);
-      if (ImGui::InputScalar("##Highlight2",ImGuiDataType_U8,&e->song.hilightB,&_ONE,&_THREE)) {
+      if (ImGui::InputScalar("##Highlight2",ImGuiDataType_U8,&e->curSubSong->hilightB,&_ONE,&_THREE)) {
         MARK_MODIFIED;
       }
 
@@ -118,11 +119,11 @@ void FurnaceGUI::drawSongInfo() {
       ImGui::Text("Pattern Length");
       ImGui::TableNextColumn();
       ImGui::SetNextItemWidth(avail);
-      int patLen=e->song.patLen;
+      int patLen=e->curSubSong->patLen;
       if (ImGui::InputInt("##PatLength",&patLen,1,3)) { MARK_MODIFIED
         if (patLen<1) patLen=1;
         if (patLen>256) patLen=256;
-        e->song.patLen=patLen;
+        e->curSubSong->patLen=patLen;
       }
 
       ImGui::TableNextRow();
@@ -130,11 +131,11 @@ void FurnaceGUI::drawSongInfo() {
       ImGui::Text("Song Length");
       ImGui::TableNextColumn();
       ImGui::SetNextItemWidth(avail);
-      int ordLen=e->song.ordersLen;
+      int ordLen=e->curSubSong->ordersLen;
       if (ImGui::InputInt("##OrdLength",&ordLen,1,3)) { MARK_MODIFIED
         if (ordLen<1) ordLen=1;
         if (ordLen>256) ordLen=256;
-        e->song.ordersLen=ordLen;
+        e->curSubSong->ordersLen=ordLen;
         if (curOrder>=ordLen) {
           setOrder(ordLen-1);
         }
@@ -147,7 +148,7 @@ void FurnaceGUI::drawSongInfo() {
       }
       ImGui::TableNextColumn();
       ImGui::SetNextItemWidth(avail);
-      float setHz=tempoView?e->song.hz*2.5:e->song.hz;
+      float setHz=tempoView?e->curSubSong->hz*2.5:e->curSubSong->hz;
       if (ImGui::InputFloat("##Rate",&setHz,1.0f,1.0f,"%g")) { MARK_MODIFIED
         if (tempoView) setHz/=2.5;
         if (setHz<10) setHz=10;
@@ -156,13 +157,13 @@ void FurnaceGUI::drawSongInfo() {
       }
       if (tempoView) {
         ImGui::TableNextColumn();
-        ImGui::Text("= %gHz",e->song.hz);
+        ImGui::Text("= %gHz",e->curSubSong->hz);
       } else {
-        if (e->song.hz>=49.98 && e->song.hz<=50.02) {
+        if (e->curSubSong->hz>=49.98 && e->curSubSong->hz<=50.02) {
           ImGui::TableNextColumn();
           ImGui::Text("PAL");
         }
-        if (e->song.hz>=59.9 && e->song.hz<=60.11) {
+        if (e->curSubSong->hz>=59.9 && e->curSubSong->hz<=60.11) {
           ImGui::TableNextColumn();
           ImGui::Text("NTSC");
         }
diff --git a/src/gui/subSongs.cpp b/src/gui/subSongs.cpp
new file mode 100644
index 000000000..21b15001f
--- /dev/null
+++ b/src/gui/subSongs.cpp
@@ -0,0 +1,94 @@
+#include "gui.h"
+#include "imgui.h"
+#include "IconsFontAwesome4.h"
+#include "misc/cpp/imgui_stdlib.h"
+
+void FurnaceGUI::drawSubSongs() {
+  if (nextWindow==GUI_WINDOW_SUBSONGS) {
+    subSongsOpen=true;
+    ImGui::SetNextWindowFocus();
+    nextWindow=GUI_WINDOW_NOTHING;
+  }
+  if (!oscOpen) return;
+  ImGui::SetNextWindowSizeConstraints(ImVec2(64.0f*dpiScale,32.0f*dpiScale),ImVec2(scrW*dpiScale,scrH*dpiScale));
+  if (ImGui::Begin("Subsongs",&subSongsOpen,ImGuiWindowFlags_NoScrollWithMouse|ImGuiWindowFlags_NoScrollbar)) {
+    char id[1024];
+    ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x-ImGui::GetFrameHeightWithSpacing()*2.0f-ImGui::GetStyle().ItemSpacing.x);
+    if (e->curSubSong->name.empty()) {
+      snprintf(id,1023,"%d. <no name>",(int)e->getCurrentSubSong()+1);
+    } else {
+      snprintf(id,1023,"%d. %s",(int)e->getCurrentSubSong()+1,e->curSubSong->name.c_str());
+    }
+    if (ImGui::BeginCombo("##SubSong",id)) {
+      for (size_t i=0; i<e->song.subsong.size(); i++) {
+        if (e->song.subsong[i]->name.empty()) {
+          snprintf(id,1023,"%d. <no name>",(int)i+1);
+        } else {
+          snprintf(id,1023,"%d. %s",(int)i+1,e->song.subsong[i]->name.c_str());
+        }
+        if (ImGui::Selectable(id,i==e->getCurrentSubSong())) {
+          e->changeSongP(i);
+          updateScroll(0);
+          oldOrder=0;
+          oldOrder1=0;
+          oldRow=0;
+          cursor.xCoarse=0;
+          cursor.xFine=0;
+          cursor.y=0;
+          selStart=cursor;
+          selEnd=cursor;
+          curOrder=0;
+        }
+      }
+      ImGui::EndCombo();
+    }
+    ImGui::SameLine();
+    if (ImGui::Button(ICON_FA_PLUS "##SubSongAdd")) {
+      if (!e->addSubSong()) {
+        showError("too many subsongs!");
+      } else {
+        e->changeSongP(e->song.subsong.size()-1);
+        updateScroll(0);
+        oldOrder=0;
+        oldOrder1=0;
+        oldRow=0;
+        cursor.xCoarse=0;
+        cursor.xFine=0;
+        cursor.y=0;
+        selStart=cursor;
+        selEnd=cursor;
+        curOrder=0;
+        MARK_MODIFIED;
+      }
+    }
+    ImGui::SameLine();
+    if (ImGui::Button(ICON_FA_MINUS "##SubSongDel")) {
+      if (!e->removeSubSong(e->getCurrentSubSong())) {
+        showError("this is the only subsong!");
+      } else {
+        undoHist.clear();
+        redoHist.clear();
+        updateScroll(0);
+        oldOrder=0;
+        oldOrder1=0;
+        oldRow=0;
+        cursor.xCoarse=0;
+        cursor.xFine=0;
+        cursor.y=0;
+        selStart=cursor;
+        selEnd=cursor;
+        curOrder=0;
+        MARK_MODIFIED;
+      }
+    }
+
+    ImGui::Text("Name");
+    ImGui::SameLine();
+    ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x);
+    if (ImGui::InputText("##SubSongName",&e->curSubSong->name)) {
+      MARK_MODIFIED;
+    }
+  }
+  if (ImGui::IsWindowFocused(ImGuiFocusedFlags_ChildWindows)) curWindow=GUI_WINDOW_SUBSONGS;
+  ImGui::End();
+}