diff --git a/src/engine/pattern.cpp b/src/engine/pattern.cpp
index f7b833e1..ea0cca7e 100644
--- a/src/engine/pattern.cpp
+++ b/src/engine/pattern.cpp
@@ -23,11 +23,7 @@
 static DivPattern emptyPat;
 
 DivPattern::DivPattern() {
-  memset(data,-1,DIV_MAX_ROWS*DIV_MAX_COLS*sizeof(short));
-  for (int i=0; i<DIV_MAX_ROWS; i++) {
-    data[i][0]=0;
-    data[i][1]=0;
-  }
+  clear();
 }
 
 DivPattern* DivChannelData::getPattern(int index, bool create) {
@@ -93,6 +89,14 @@ void DivPattern::copyOn(DivPattern* dest) {
   memcpy(dest->data,data,sizeof(data));
 }
 
+void DivPattern::clear() {
+  memset(data,-1,DIV_MAX_ROWS*DIV_MAX_COLS*sizeof(short));
+  for (int i=0; i<DIV_MAX_ROWS; i++) {
+    data[i][0]=0;
+    data[i][1]=0;
+  }
+}
+
 DivChannelData::DivChannelData():
   effectCols(1) {
   memset(data,0,DIV_MAX_PATTERNS*sizeof(void*));
diff --git a/src/engine/pattern.h b/src/engine/pattern.h
index 64439986..257ce7ec 100644
--- a/src/engine/pattern.h
+++ b/src/engine/pattern.h
@@ -24,6 +24,11 @@ struct DivPattern {
   String name;
   short data[DIV_MAX_ROWS][DIV_MAX_COLS];
 
+  /**
+   * clear the pattern.
+   */
+  void clear();
+
   /**
    * copy this pattern to another.
    * @param dest the destination pattern.
diff --git a/src/gui/doAction.cpp b/src/gui/doAction.cpp
index 64d1bab0..16884d70 100644
--- a/src/gui/doAction.cpp
+++ b/src/gui/doAction.cpp
@@ -561,18 +561,32 @@ void FurnaceGUI::doAction(int what) {
       doFlip();
       break;
     case GUI_ACTION_PAT_COLLAPSE_ROWS:
-      doCollapse(2);
+      doCollapse(2,selStart,selEnd);
       break;
     case GUI_ACTION_PAT_EXPAND_ROWS:
-      doExpand(2);
+      doExpand(2,selStart,selEnd);
       break;
-    case GUI_ACTION_PAT_COLLAPSE_PAT: // TODO
+    case GUI_ACTION_PAT_COLLAPSE_PAT: {
+      SelectionPoint selEndPat;
+      selEndPat.xCoarse=e->getTotalChannelCount()-1;
+      selEndPat.xFine=2+e->curPat[selEndPat.xCoarse].effectCols*2;
+      selEndPat.y=e->curSubSong->patLen-1;
+      doCollapse(2,SelectionPoint(0,0,0),selEndPat);
       break;
-    case GUI_ACTION_PAT_EXPAND_PAT: // TODO
+    }
+    case GUI_ACTION_PAT_EXPAND_PAT: {
+      SelectionPoint selEndPat;
+      selEndPat.xCoarse=e->getTotalChannelCount()-1;
+      selEndPat.xFine=2+e->curPat[selEndPat.xCoarse].effectCols*2;
+      selEndPat.y=e->curSubSong->patLen-1;
+      doExpand(2,SelectionPoint(0,0,0),selEndPat);
       break;
-    case GUI_ACTION_PAT_COLLAPSE_SONG: // TODO
+    }
+    case GUI_ACTION_PAT_COLLAPSE_SONG:
+      doCollapseSong(2);
       break;
-    case GUI_ACTION_PAT_EXPAND_SONG: // TODO
+    case GUI_ACTION_PAT_EXPAND_SONG:
+      doExpandSong(2);
       break;
     case GUI_ACTION_PAT_LATCH: // TODO
       break;
diff --git a/src/gui/editing.cpp b/src/gui/editing.cpp
index 77d76da2..1a2b1b11 100644
--- a/src/gui/editing.cpp
+++ b/src/gui/editing.cpp
@@ -67,6 +67,9 @@ void FurnaceGUI::prepareUndo(ActionType action) {
         e->curPat[i].getPattern(e->curOrders->ord[i][curOrder],false)->copyOn(oldPat[i]);
       }
       break;
+    case GUI_UNDO_PATTERN_COLLAPSE_SONG:
+    case GUI_UNDO_PATTERN_EXPAND_SONG: // TODO
+      break;
     case GUI_UNDO_REPLACE: // this is handled by doReplace()
       break;
   }
@@ -130,6 +133,9 @@ void FurnaceGUI::makeUndo(ActionType action) {
         doPush=true;
       }
       break;
+    case GUI_UNDO_PATTERN_COLLAPSE_SONG:
+    case GUI_UNDO_PATTERN_EXPAND_SONG: // TODO
+      break;
     case GUI_UNDO_REPLACE: // this is handled by doReplace()
       break;
   }
@@ -839,50 +845,56 @@ void FurnaceGUI::doFlip() {
   makeUndo(GUI_UNDO_PATTERN_FLIP);
 }
 
-void FurnaceGUI::doCollapse(int divider) {
+void FurnaceGUI::doCollapse(int divider, const SelectionPoint& sStart, const SelectionPoint& sEnd) {
+  if (divider<2) return;
+  if (e->curSubSong->patLen<divider) {
+    showError("can't collapse any further!");
+    return;
+  }
+
   finishSelection();
   prepareUndo(GUI_UNDO_PATTERN_COLLAPSE);
 
   DivPattern patBuffer;
-  int iCoarse=selStart.xCoarse;
-  int iFine=selStart.xFine;
-  for (; iCoarse<=selEnd.xCoarse; iCoarse++) {
+  int iCoarse=sStart.xCoarse;
+  int iFine=sStart.xFine;
+  for (; iCoarse<=sEnd.xCoarse; iCoarse++) {
     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++) {
+    for (; iFine<3+e->curPat[iCoarse].effectCols*2 && (iCoarse<sEnd.xCoarse || iFine<=sEnd.xFine); iFine++) {
       maskOut(opMaskCollapseExpand,iFine);
-      for (int j=selStart.y; j<=selEnd.y; j++) {
+      for (int j=sStart.y; j<=sEnd.y; j++) {
         if (iFine==0) {
           patBuffer.data[j][0]=pat->data[j][0];
         }
         patBuffer.data[j][iFine+1]=pat->data[j][iFine+1];
       }
-      for (int j=0; j<=selEnd.y-selStart.y; j++) {
-        if (j*divider>=selEnd.y-selStart.y) {
+      for (int j=0; j<=sEnd.y-sStart.y; j++) {
+        if (j*divider>=sEnd.y-sStart.y) {
           if (iFine==0) {
-            pat->data[j+selStart.y][0]=0;
-            pat->data[j+selStart.y][1]=0;
+            pat->data[j+sStart.y][0]=0;
+            pat->data[j+sStart.y][1]=0;
           } else {
-            pat->data[j+selStart.y][iFine+1]=-1;
+            pat->data[j+sStart.y][iFine+1]=-1;
           }
         } else {
           if (iFine==0) {
-            pat->data[j+selStart.y][0]=patBuffer.data[j*divider+selStart.y][0];
+            pat->data[j+sStart.y][0]=patBuffer.data[j*divider+sStart.y][0];
           }
-          pat->data[j+selStart.y][iFine+1]=patBuffer.data[j*divider+selStart.y][iFine+1];
+          pat->data[j+sStart.y][iFine+1]=patBuffer.data[j*divider+sStart.y][iFine+1];
 
           if (iFine==0) {
             for (int k=1; k<divider; k++) {
-              if ((j*divider+k)>=selEnd.y-selStart.y) break;
-              if (!(pat->data[j+selStart.y][0]==0 && pat->data[j+selStart.y][1]==0)) break;
-              pat->data[j+selStart.y][0]=patBuffer.data[j*divider+selStart.y+k][0];
-              pat->data[j+selStart.y][1]=patBuffer.data[j*divider+selStart.y+k][1];
+              if ((j*divider+k)>=sEnd.y-sStart.y) break;
+              if (!(pat->data[j+sStart.y][0]==0 && pat->data[j+sStart.y][1]==0)) break;
+              pat->data[j+sStart.y][0]=patBuffer.data[j*divider+sStart.y+k][0];
+              pat->data[j+sStart.y][1]=patBuffer.data[j*divider+sStart.y+k][1];
             }
           } else {
             for (int k=1; k<divider; k++) {
-              if ((j*divider+k)>=selEnd.y-selStart.y) break;
-              if (pat->data[j+selStart.y][iFine+1]!=-1) break;
-              pat->data[j+selStart.y][iFine+1]=patBuffer.data[j*divider+selStart.y+k][iFine+1];
+              if ((j*divider+k)>=sEnd.y-sStart.y) break;
+              if (pat->data[j+sStart.y][iFine+1]!=-1) break;
+              pat->data[j+sStart.y][iFine+1]=patBuffer.data[j*divider+sStart.y+k][iFine+1];
             }
           }
         }
@@ -894,41 +906,41 @@ void FurnaceGUI::doCollapse(int divider) {
   makeUndo(GUI_UNDO_PATTERN_COLLAPSE);
 }
 
-void FurnaceGUI::doExpand(int multiplier) {
-  if (multiplier<1) return;
+void FurnaceGUI::doExpand(int multiplier, const SelectionPoint& sStart, const SelectionPoint& sEnd) {
+  if (multiplier<2) return;
 
   finishSelection();
   prepareUndo(GUI_UNDO_PATTERN_EXPAND);
 
   DivPattern patBuffer;
-  int iCoarse=selStart.xCoarse;
-  int iFine=selStart.xFine;
-  for (; iCoarse<=selEnd.xCoarse; iCoarse++) {
+  int iCoarse=sStart.xCoarse;
+  int iFine=sStart.xFine;
+  for (; iCoarse<=sEnd.xCoarse; iCoarse++) {
     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++) {
+    for (; iFine<3+e->curPat[iCoarse].effectCols*2 && (iCoarse<sEnd.xCoarse || iFine<=sEnd.xFine); iFine++) {
       maskOut(opMaskCollapseExpand,iFine);
-      for (int j=selStart.y; j<=selEnd.y; j++) {
+      for (int j=sStart.y; j<=sEnd.y; j++) {
         if (iFine==0) {
           patBuffer.data[j][0]=pat->data[j][0];
         }
         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->curSubSong->patLen) break;
+      for (int j=0; j<=(sEnd.y-sStart.y)*multiplier; j++) {
+        if ((j+sStart.y)>=e->curSubSong->patLen) break;
         if ((j%multiplier)!=0) {
           if (iFine==0) {
-            pat->data[j+selStart.y][0]=0;
-            pat->data[j+selStart.y][1]=0;
+            pat->data[j+sStart.y][0]=0;
+            pat->data[j+sStart.y][1]=0;
           } else {
-            pat->data[j+selStart.y][iFine+1]=-1;
+            pat->data[j+sStart.y][iFine+1]=-1;
           }
           continue;
         }
         if (iFine==0) {
-          pat->data[j+selStart.y][0]=patBuffer.data[j/multiplier+selStart.y][0];
+          pat->data[j+sStart.y][0]=patBuffer.data[j/multiplier+sStart.y][0];
         }
-        pat->data[j+selStart.y][iFine+1]=patBuffer.data[j/multiplier+selStart.y][iFine+1];
+        pat->data[j+sStart.y][iFine+1]=patBuffer.data[j/multiplier+sStart.y][iFine+1];
       }
     }
     iFine=0;
@@ -937,6 +949,162 @@ void FurnaceGUI::doExpand(int multiplier) {
   makeUndo(GUI_UNDO_PATTERN_EXPAND);
 }
 
+void FurnaceGUI::doCollapseSong(int divider) {
+  if (divider<2) return;
+  finishSelection();
+
+  UndoStep us;
+  us.type=GUI_UNDO_PATTERN_COLLAPSE_SONG;
+
+  DivPattern patCopy;
+
+  size_t subSong=e->getCurrentSubSong();
+  for (int i=0; i<e->getTotalChannelCount(); i++) {
+    for (int j=0; j<DIV_MAX_PATTERNS; j++) {
+      if (e->curPat[i].data[j]==NULL) continue;
+
+      DivPattern* pat=e->curPat[i].getPattern(j,true);
+      pat->copyOn(&patCopy);
+      pat->clear();
+      for (int k=0; k<DIV_MAX_ROWS; k++) {
+        for (int l=0; l<DIV_MAX_COLS; l++) {
+          if (l==0) {
+            if (!(pat->data[k/divider][0]==0 && pat->data[k/divider][1]==0)) continue;
+          } else {
+            if (pat->data[k/divider][l+1]!=-1) continue;
+          }
+
+          if (l==0) {
+            pat->data[k/divider][l]=patCopy.data[k][l];
+          }
+          pat->data[k/divider][l+1]=patCopy.data[k][l+1];
+
+          if (l>3 && !(l&1)) { // scale effects as needed
+            switch (pat->data[k/divider][l]) {
+              case 0x0d:
+                pat->data[k/divider][l+1]/=divider;
+                break;
+              case 0x0f:
+                pat->data[k/divider][l+1]=CLAMP(pat->data[k/divider][l+1]*divider,1,255);
+                break;
+            }
+          }
+        }
+      }
+
+      // put undo
+      for (int k=0; k<DIV_MAX_ROWS; k++) {
+        for (int l=0; l<DIV_MAX_COLS; l++) {
+          if (pat->data[k][l]!=patCopy.data[k][l]) {
+            us.pat.push_back(UndoPatternData(subSong,i,j,k,l,patCopy.data[k][l],pat->data[k][l]));
+          }
+        }
+      }
+    }
+  }
+  // magic
+  unsigned char* subSongInfoCopy=new unsigned char[1024];
+  memcpy(subSongInfoCopy,e->curSubSong,1024);
+  e->curSubSong->patLen/=divider;
+  for (int i=0; i<e->curSubSong->speeds.len; i++) {
+    e->curSubSong->speeds.val[i]=CLAMP(e->curSubSong->speeds.val[i]*divider,1,255);
+  }
+  unsigned char* newSubSongInfo=(unsigned char*)e->curSubSong;
+  for (int i=0; i<1024; i++) {
+    if (subSongInfoCopy[i]!=newSubSongInfo[i]) {
+      us.other.push_back(UndoOtherData(GUI_UNDO_TARGET_SUBSONG,subSong,i,subSongInfoCopy[i],newSubSongInfo[i]));
+    }
+  }
+
+  if (!us.pat.empty()) {
+    undoHist.push_back(us);
+    redoHist.clear();
+    if (undoHist.size()>settings.maxUndoSteps) undoHist.pop_front();
+  }
+  
+  if (e->isPlaying()) e->play();
+}
+
+void FurnaceGUI::doExpandSong(int multiplier) {
+  if (multiplier<2) return;
+  if (e->curSubSong->patLen>(256/multiplier)) {
+    showError("can't expand any further!");
+    return;
+  }
+  finishSelection();
+
+  UndoStep us;
+  us.type=GUI_UNDO_PATTERN_EXPAND_SONG;
+
+  DivPattern patCopy;
+
+  size_t subSong=e->getCurrentSubSong();
+  for (int i=0; i<e->getTotalChannelCount(); i++) {
+    for (int j=0; j<DIV_MAX_PATTERNS; j++) {
+      if (e->curPat[i].data[j]==NULL) continue;
+
+      DivPattern* pat=e->curPat[i].getPattern(j,true);
+      pat->copyOn(&patCopy);
+      pat->clear();
+      for (int k=0; k<(256/multiplier); k++) {
+        for (int l=0; l<DIV_MAX_COLS; l++) {
+          if (l==0) {
+            if (!(pat->data[k*multiplier][0]==0 && pat->data[k*multiplier][1]==0)) continue;
+          } else {
+            if (pat->data[k*multiplier][l+1]!=-1) continue;
+          }
+
+          if (l==0) {
+            pat->data[k*multiplier][l]=patCopy.data[k][l];
+          }
+          pat->data[k*multiplier][l+1]=patCopy.data[k][l+1];
+
+          if (l>3 && !(l&1)) { // scale effects as needed
+            switch (pat->data[k*multiplier][l]) {
+              case 0x0d:
+                pat->data[k*multiplier][l+1]/=multiplier;
+                break;
+              case 0x0f:
+                pat->data[k*multiplier][l+1]=CLAMP(pat->data[k*multiplier][l+1]/multiplier,1,255);
+                break;
+            }
+          }
+        }
+      }
+
+      // put undo
+      for (int k=0; k<DIV_MAX_ROWS; k++) {
+        for (int l=0; l<DIV_MAX_COLS; l++) {
+          if (pat->data[k][l]!=patCopy.data[k][l]) {
+            us.pat.push_back(UndoPatternData(subSong,i,j,k,l,patCopy.data[k][l],pat->data[k][l]));
+          }
+        }
+      }
+    }
+  }
+  // magic
+  unsigned char* subSongInfoCopy=new unsigned char[1024];
+  memcpy(subSongInfoCopy,e->curSubSong,1024);
+  e->curSubSong->patLen*=multiplier;
+  for (int i=0; i<e->curSubSong->speeds.len; i++) {
+    e->curSubSong->speeds.val[i]=CLAMP(e->curSubSong->speeds.val[i]/multiplier,1,255);
+  }
+  unsigned char* newSubSongInfo=(unsigned char*)e->curSubSong;
+  for (int i=0; i<1024; i++) {
+    if (subSongInfoCopy[i]!=newSubSongInfo[i]) {
+      us.other.push_back(UndoOtherData(GUI_UNDO_TARGET_SUBSONG,subSong,i,subSongInfoCopy[i],newSubSongInfo[i]));
+    }
+  }
+
+  if (!us.pat.empty()) {
+    undoHist.push_back(us);
+    redoHist.clear();
+    if (undoHist.size()>settings.maxUndoSteps) undoHist.pop_front();
+  }
+
+  if (e->isPlaying()) e->play();
+}
+
 void FurnaceGUI::doDrag() {
   int len=dragEnd.xCoarse-dragStart.xCoarse+1;
 
@@ -985,6 +1153,8 @@ void FurnaceGUI::doUndo() {
     case GUI_UNDO_PATTERN_FLIP:
     case GUI_UNDO_PATTERN_COLLAPSE:
     case GUI_UNDO_PATTERN_EXPAND:
+    case GUI_UNDO_PATTERN_COLLAPSE_SONG:
+    case GUI_UNDO_PATTERN_EXPAND_SONG:
     case GUI_UNDO_PATTERN_DRAG:
     case GUI_UNDO_REPLACE:
       for (UndoPatternData& i: us.pat) {
@@ -1005,6 +1175,22 @@ void FurnaceGUI::doUndo() {
       break;
   }
 
+  bool shallReplay=false;
+  for (UndoOtherData& i: us.other) {
+    switch (i.target) {
+      case GUI_UNDO_TARGET_SONG:
+        ((unsigned char*)(&e->song))[i.off]=i.oldVal;
+        shallReplay=true;
+        break;
+      case GUI_UNDO_TARGET_SUBSONG:
+        if (i.subtarget<0 || i.subtarget>=(int)e->song.subsong.size()) break;
+        ((unsigned char*)(e->song.subsong[i.subtarget]))[i.off]=i.oldVal;
+        shallReplay=true;
+        break;
+    }
+  }
+  if (shallReplay && e->isPlaying()) play();
+
   if (curOrder>=e->curSubSong->ordersLen) {
     curOrder=e->curSubSong->ordersLen-1;
     oldOrder=curOrder;
@@ -1045,6 +1231,8 @@ void FurnaceGUI::doRedo() {
     case GUI_UNDO_PATTERN_COLLAPSE:
     case GUI_UNDO_PATTERN_EXPAND:
     case GUI_UNDO_PATTERN_DRAG:
+    case GUI_UNDO_PATTERN_COLLAPSE_SONG:
+    case GUI_UNDO_PATTERN_EXPAND_SONG:
     case GUI_UNDO_REPLACE:
       for (UndoPatternData& i: us.pat) {
         e->changeSongP(i.subSong);
@@ -1065,6 +1253,22 @@ void FurnaceGUI::doRedo() {
       break;
   }
 
+  bool shallReplay=false;
+  for (UndoOtherData& i: us.other) {
+    switch (i.target) {
+      case GUI_UNDO_TARGET_SONG:
+        ((unsigned char*)(&e->song))[i.off]=i.newVal;
+        shallReplay=true;
+        break;
+      case GUI_UNDO_TARGET_SUBSONG:
+        if (i.subtarget<0 || i.subtarget>=(int)e->song.subsong.size()) break;
+        ((unsigned char*)(e->song.subsong[i.subtarget]))[i.off]=i.newVal;
+        shallReplay=true;
+        break;
+    }
+  }
+  if (shallReplay && e->isPlaying()) play();
+
   if (curOrder>=e->curSubSong->ordersLen) {
     curOrder=e->curSubSong->ordersLen-1;
     oldOrder=curOrder;
diff --git a/src/gui/gui.cpp b/src/gui/gui.cpp
index 76214fae..39a7b1cd 100644
--- a/src/gui/gui.cpp
+++ b/src/gui/gui.cpp
@@ -2842,9 +2842,23 @@ void FurnaceGUI::editOptions(bool topMenu) {
     ImGui::Separator();
 
     if (ImGui::MenuItem("flip selection",BIND_FOR(GUI_ACTION_PAT_FLIP_SELECTION))) doFlip();
-    if (ImGui::MenuItem("collapse",BIND_FOR(GUI_ACTION_PAT_COLLAPSE_ROWS))) doCollapse(2);
-    if (ImGui::MenuItem("expand",BIND_FOR(GUI_ACTION_PAT_EXPAND_ROWS))) doExpand(2);
+    if (ImGui::MenuItem("collapse",BIND_FOR(GUI_ACTION_PAT_COLLAPSE_ROWS))) doCollapse(2,selStart,selEnd);
+    if (ImGui::MenuItem("expand",BIND_FOR(GUI_ACTION_PAT_EXPAND_ROWS))) doExpand(2,selStart,selEnd);
 
+    if (topMenu) {
+      ImGui::Separator();
+      if (ImGui::MenuItem("collapse pattern",BIND_FOR(GUI_ACTION_PAT_COLLAPSE_PAT))) doAction(GUI_ACTION_PAT_COLLAPSE_PAT);
+      if (ImGui::MenuItem("expand pattern",BIND_FOR(GUI_ACTION_PAT_EXPAND_PAT))) doAction(GUI_ACTION_PAT_EXPAND_PAT);
+    }
+  }
+
+  if (topMenu) {
+    ImGui::Separator();
+    if (ImGui::MenuItem("collapse song",BIND_FOR(GUI_ACTION_PAT_COLLAPSE_SONG))) doAction(GUI_ACTION_PAT_COLLAPSE_SONG);
+    if (ImGui::MenuItem("expand song",BIND_FOR(GUI_ACTION_PAT_EXPAND_SONG))) doAction(GUI_ACTION_PAT_EXPAND_SONG);
+  }
+
+  if (!basicMode) {
     if (topMenu) {
       ImGui::Separator();
       if (ImGui::MenuItem("find/replace",BIND_FOR(GUI_ACTION_WINDOW_FIND),findOpen)) {
@@ -2856,16 +2870,6 @@ void FurnaceGUI::editOptions(bool topMenu) {
       }
     }
   }
-
-  /*if (topMenu) {
-    ImGui::Separator();
-    ImGui::MenuItem("collapse pattern",BIND_FOR(GUI_ACTION_PAT_COLLAPSE_PAT));
-    ImGui::MenuItem("expand pattern",BIND_FOR(GUI_ACTION_PAT_EXPAND_PAT));
-
-    ImGui::Separator();
-    ImGui::MenuItem("collapse song",BIND_FOR(GUI_ACTION_PAT_COLLAPSE_SONG));
-    ImGui::MenuItem("expand song",BIND_FOR(GUI_ACTION_PAT_EXPAND_SONG));
-  }*/
 }
 
 void FurnaceGUI::toggleMobileUI(bool enable, bool force) {
diff --git a/src/gui/gui.h b/src/gui/gui.h
index fe44ea26..df6700a8 100644
--- a/src/gui/gui.h
+++ b/src/gui/gui.h
@@ -721,6 +721,8 @@ enum NoteCtrl {
 struct SelectionPoint {
   int xCoarse, xFine;
   int y;
+  SelectionPoint(int xc, int xf, int yp):
+    xCoarse(xc), xFine(xf), y(yp) {}
   SelectionPoint():
     xCoarse(0), xFine(0), y(0) {}
 };
@@ -742,10 +744,17 @@ enum ActionType {
   GUI_UNDO_PATTERN_FLIP,
   GUI_UNDO_PATTERN_COLLAPSE,
   GUI_UNDO_PATTERN_EXPAND,
+  GUI_UNDO_PATTERN_COLLAPSE_SONG,
+  GUI_UNDO_PATTERN_EXPAND_SONG,
   GUI_UNDO_PATTERN_DRAG,
   GUI_UNDO_REPLACE
 };
 
+enum UndoOtherTarget {
+  GUI_UNDO_TARGET_SONG,
+  GUI_UNDO_TARGET_SUBSONG
+};
+
 struct UndoPatternData {
   int subSong, chan, pat, row, col;
   short oldVal, newVal;
@@ -770,6 +779,19 @@ struct UndoOrderData {
     newVal(v2) {}
 };
 
+struct UndoOtherData {
+  UndoOtherTarget target;
+  int subtarget;
+  size_t off;
+  unsigned char oldVal, newVal;
+  UndoOtherData(UndoOtherTarget t, int st, size_t o, unsigned char v1, unsigned char v2):
+    target(t),
+    subtarget(st),
+    off(o),
+    oldVal(v1),
+    newVal(v2) {}
+};
+
 struct UndoStep {
   ActionType type;
   SelectionPoint cursor, selStart, selEnd;
@@ -779,6 +801,7 @@ struct UndoStep {
   int oldPatLen, newPatLen;
   std::vector<UndoOrderData> ord;
   std::vector<UndoPatternData> pat;
+  std::vector<UndoOtherData> other;
 };
 
 // -1 = any
@@ -2064,8 +2087,10 @@ class FurnaceGUI {
   void doScale(float top);
   void doRandomize(int bottom, int top, bool mode);
   void doFlip();
-  void doCollapse(int divider);
-  void doExpand(int multiplier);
+  void doCollapse(int divider, const SelectionPoint& sStart, const SelectionPoint& sEnd);
+  void doExpand(int multiplier, const SelectionPoint& sStart, const SelectionPoint& sEnd);
+  void doCollapseSong(int divider);
+  void doExpandSong(int multiplier);
   void doUndo();
   void doRedo();
   void doFind();