What MIDI is?
MIDI (see more specifics) is a protocol in binary form, a sort of music description language. All MIDI compatible instruments (see computers, keyboards, disklavier and other music instruments) can dialogue amongts each other. The main informations a MIDI can send are the note on (to sound a note) and the note off (to stop the note), its velocity (to determine how loud it plays). Music delivered by MIDI files is the most common use of MIDI today.
The "reason MIDI files are so popular is that, unlike digital audio files (.wav, .mp3, etc.) or even CD's, a MIDI file does not need to capture and store actual sounds. Instead, the MIDI file can be a list of events which describe the specific steps that a soundcard or other playback device must take to generate certain sounds. MIDI files are generally much smaller than digital audio files, and the events are also editable, allowing the music to be rearranged, edited, even composed" (youthtech) and printed.
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