MIDI
MIDI stands for Musical Instrument Digital Interface. Instead of storing the recorded music, MIDI files just store instructions for playing the music--like sheet music you might give to a band. MIDI files are very small.
(you can stop copying here)
When you play a MIDI file on your computer, your computer is acting like a live band. It's actually reading the notes and playing the virtual instruments. It's not recorded music.
Really expensive MIDI software and equipment can make great-sounding music.
Unfortunately, the default MIDI software that comes with everybody's computer often makes it sound like a really cheesy live band.
Examples:
Cheesy-sounding rendering of Patsy Cline's "Crazy."
AC/DC's "Thunderstruck" sounds better on my computer--especially the lead guitar at the beginning.
Try pausing the file while playing. Sound odd? You heard the echo die out because the computer was actually playing the music, as a musician would; you weren't listening to a recording.
Both of these MIDI files were accessed from (mididb.com) on 10/23/07.