Initial "concepts and terms" doc.

doc/1-intro/README.md

@@ -6,13 +6,15 @@ it has a large selection of features and sound chips. from the NES, SNES and Gen
 
 every chip is emulated using many emulation cores, therefore the sound that Furnace produces is authentic to that of real hardware.
 
+
+
 ## hexadecimal
 
 Furnace uses hexadecimal (abbreviated as "hex") numbers frequently. see [this guide](hex.md) for a crash course.
 
 ## interface
 
-Furnace uses a music tracker interface. think of a table with music notes written on it. then that table scrolls up and plays the notes.
+Furnace uses a music tracker interface. think of a table with music notes written on it. then that table scrolls up and plays the notes. even experienced tracker musicians might benefit from a quick review of [tracker concepts and terms](concepts.md) before using Furnace.
 
 due to its nature of being feature-packed, it may be technical and somewhat difficult to get around. therefore we added a basic mode, which hides several advanced features.
 

doc/1-intro/concepts.md

@@ -0,0 +1,36 @@
+# concepts and terms
+
+- A **module** is a file for a tracker that contains at least one **song**.
+- Each Furnace module involves at least one **[chip](../7-systems/README.md)**, an emulation of a specific audio processor.
+
+## tracking
+
+The **[pattern view](../3-pattern/README.md)** is like a spreadsheet that displays the following:
+- Each labeled column represents a **channel** of sound provided by the chips in use.
+- Each **note** starts a sound playing. Within a channel, only one note can play at a time.
+- Each note is assigned an **[instrument](../4-instrument/README.md)** which describes what it will sound like.
+- An **effect** is a command that changes some aspect of playback. It can alter note pitch, volume, timing, and more.
+- An instrument **macro** is an automated sequence of effects that applies to every note of that instrument.
+
+## structure
+
+The **order list** is a smaller spreadsheet showing the overall song structure.
+- A song is made up of a list of **orders**.
+- An **order** is a set of numbered **patterns** used for each channel.
+- Each channel has its own unique list of patterns.
+- Each pattern contains note and effect data for that channel only.
+- Patterns may be used multiple times in the order list. Changing a pattern's data in one order will affect the same pattern used in other orders.
+
+## time
+
+- Each pattern is made of the same number of **rows** as seen in the tracker view.
+- During playback, Each row lasts a number of **ticks** determined by its **speed** value.
+- A tick is the smallest measure of time to which all note, effect, and macro times are quantized.
+
+## sound
+
+Different chips have different capabilities. Even within the same chip, each channel may have its own ways of making sound.
+- Some channels use one or more waveform **generators** (sine, square, noise...) to build up a sound.
+- Of special note are **[FM (frequency modulation)](../4-instrument/fm.md)** channels, which use a number of generators called **operators** that can interact to make very complex sounds.
+- Some channels use **[samples](../6-sample/README.md)** – recordings of sounds, often with defined loop points to allow a note to sustain.
+- Some channels use **[wavetables](../5-wave/README.md)**, which are like very short samples of fixed length that automatically loop.