Rom map (code/initial.s)

Range	Descrip
04c1-04dd	Calls to exchange sound effect+attrs data with the SNES
04f1-04fb	As above, for music
0518-0527	Generic routine for the 4 above, for exchanging data with the SNES
0528-058f	Routine for handling VCMD's between $80 and $df
05e1-0605	Example 16bit by 16bit multiplication that happens in a bunch of places
0632-065e	Music $ff (load new data, eg for SOU_TRN), and PlayNewMusic
065f-0696	ResetAllTracks
06a6-06c8	Music $fe (stop and jump to real IPL)
06cb-07bb	ProcessMusicScore (checks curr phrase, then the track for 8 instruments)
07bd-0809	tempo, echo volume, and master volume fade is processed
080a-0add	VCMD handlers
0b05-0b42	VCMD handler table
0b43-0b61	VCMD num params table
0bed-0c2a	ApplyPanAndSetVolRegs
0c2b-0d75	TickTrackUpdate
0dae-0dbf	ApplyTremoloToVolsAndVelocity
0dc0-0dd4	VolPanLevels table
0dd5-0df4	FilterCoefficients table
0e09-0e22	Octave0NotePitches table
0e2e-0e79	MimicIPL
0ef0-0f66	Outer sound effect+attr process code

At the bottom of the file you have:

• SoundScoreArea: in data/scores.s, is example N-SPC music data
• SampleSrcDir: ie DIR
• NoteDurationRates: default counters for the 8 note length values
• NoteVelocityRates: ??
• InstrumentsData: https://sneslab.net/wiki/N-SPC_Engine#Instrument_Format
• Various samples in data/samples.s