When I started writing music, It was difficult for me to know which MIDI voice to use...especially when the instrument was supposed to be used in lieu of a human voice. Trying the different MIDI voices was very time consuming. To avoid that, and in a "dead spot" incomposing ideas, I made up these two Personal Composer files. To view these, you must have either Personal Composer, or the free PCViewer  which you can obtain at pcomposer.com

A standard set of 128 (Usually 0-127) sounds (Voices or Patches) for MIDI sound cards and devices (synthesizers, sound modules, lighting control, & etc.). By assigning instruments to specific MIDI patch (voice) tocations, General MIDI provides a standard way of communicating MIDI sound. Other voice sets arw available, but I use General MIDI with Creative Labs Sound Blaster Audigy Sound Card.

The reason for this is that in my "Osiris" ballet, I use a full symphony orchestra in a 25 staff format so the 16 MIDI channels on Port A are not enough. See the full Overture from Osiris as PDF file. You must change size to 100% to see it Notice that every staff is labeled "Port-Channel-Voice." Thus Staff 1 is Piccalo at A-1-73 (Stem up), and Flute III A-2-72 (Stem Down.)

The General MIDI Percussion Setis different. It is always on Channel 10, and the type of drum is set by the note pitch value. (Middle C4 is always a Hi Bongo, C5 a Long Whistle, & etc. The Note type, ie: 1/4 note. 1/2 note, &etc. determine the length of time...subject to the attack / decay charististics of the drum used. Trills and drum rolls are handled diferently by each system. Single pitch percussion instruments are often written with an "X" notehead. Percussion instruments with varying pitch such as Timoani and Marimbas are written on seperate staffs in standard notation.