What are compressed MIDI files ?
A compressed MIDI file is a ZIP, RAR, ARJ, or GZIP file containing one MIDI file. MIDI files compress very nicely so compressing them can be very useful and can save a lot of disk space. You can compress any of the supported MIDI formats. Use .MIZ file extension for all compressed MIDIs. (Note, however, that most (if not all) other programs will be unable to play any of these compressed MIDIs.