General MIDI
More info
- Creator
- MIDI Manufacturers Association, JMSC
- Released
- 1991
- Type
- Standard
- Successor
- General MIDI 2 (1999)
The addendum to MIDI that fixed which instrument each program number should be, so a song sounds roughly the same on any synth module.
MIDI only says "switch to program 25" — what program 25 actually was used to be up to each manufacturer, so a file written for one synth could play piano on the string part of another. In 1991 General MIDI pinned down a list of 128 instruments (1 is a grand piano, 25 a nylon-string guitar), made channel 10 always drums with a fixed key map, and required a GM module to handle at least 24 simultaneous voices.
That made MIDI files a practical format for game music and web pages through the 1990s. Roland GS and Yamaha XG extended it with more sounds and effects, and Roland's Sound Canvas SC-55 became the reference composers wrote for. It's why the same DOS game sounds so different on an FM-synthesis Sound Blaster than on a real Roland module.