What is MIDI ?

Introduction:
The Midi standard was developed to make synthesizers and other electronic musical equipment communicate with each other. The data is transmitted through the synthesizer's midi port. It contains information, how long and with which intensity a key is pressed, which instrument is playing, which drums to play, and so on. The instruments are stored in several banks with 128 instruments each. Depending on the synthesizer, you can load your own samples somewhere, too. The synthesizer which receives the data has only to load the same instrument at the proper postion. This gives the possibility to store the music in files and swap them with your fellow musicians. The file format is also standardized and is known as the Standard Midi File format (SMF). Generally, the "midis / midi files" you know so well are all SMFs. However, most of them assume the General Midi instrument set for compatibility with other GM sound equipment.

Midi light: General Midi
Of course, not everybody is willing to spend much money for a synthesizer. So let's better buy a soundcard for our computer! The General Midi standard enables a wide variety of soundcards to play the file. However, it applies some restrictions to the original Midi standard: There's only one bank of 128 predefined Midi instruments available. All soundcards with General Midi support have to be able to play these instruments. If you have a RAM based soundcard, which can load own samples in its memory, you can perhaps cheat and have your Midi file played with other "instruments", but don't expect others to own the same soundcard.

Enhancements
Some companies defined their own midi "standards" superceding the original standard, usually adding new instruments, drum kits, etc. The most well-known are the GS format (by Roland) and the XM format (by Yamaha). Both formats are downward compatible to General Midi.

Newsgroups:
Here are some newsgroups you might consider interesting:

Midi files:		alt.binaries.sounds.midi
Discussion (German)	maus.midi
Synthesizer market:	rec.music.makers.marketplace
Discussion (English)	rec.music.makers.synth

Back to Listener's Section

Taro Rehrl (e-mail), 1994-09-15, 1999-06-28