Yamaha uses a different MIDI patch numbering system.

Whereas most synths use the Roland "one based" system, where the Grand Piano is 001 and goes thru to 128 at the last instrument, Yamaha is "zero based" and the Grand Piano is 000 with the last instrument being 127.

This has nothing to do with "Type 1" or "Type 0" MIDI files. Type 1 is multitracked, Type 0 saves all the tracks on one track.

Your Yamaha may also use a different MIDI channel for drums than channel 10, although that is a rather older thing. Likely the drums sounded weird because you were attempting to play back a Roland one based file on the Yamaha's zero based synth.

The manual for your keyboard will tell you where the patches start and stop. Yamaha only made a small handful of keyboards that had the "GM" sticker on them and would work with one based.


--Mac