Music File Format

structure of a .mus file

Offset00: BYTE the value 0x00 (i think this indicates that this is a .mus file, picture files are identified by 02)
Offset01: BYTE the value 0x01 (i believe this is the number of music sequences in the file. there is a similar byte like this in a .pic file, indicating the number of pictures in the file)
Offset02: WORD the length of the musical sequence. This value will be a multiple of 2.
Offset04: music data, with (note,length) pairs until the end of the file

As far as i've been able to tell, the value 0x08 is C-4 on the midi scale, and increases/decreases in half-steps. 0xFF is a pause. i'm not sure what the lengths are measured in, but 0x20 is a pretty decent quarter note.