MIDI Note Player

Arduino Play MIDI

http://arduino.cc/en/Tutorial/Midi

Tutorial on MIDI and Music Synthesis

http://www.harmony-central.com/MIDI/Doc/tutorial.html#messages

The General MIDI system utilizes MIDI Channels 1-9 and 11-16 for chromatic instrument sounds, while Channel number 10 is utilized for "key-based" percussion sounds. These instrument sounds are grouped into "sets" of related sounds. For example, program numbers 1-8 are piano sounds, 9-16 are chromatic percussion sounds, 17-24 are organ sounds, 25-32 are guitar sounds, etc.