Contrary to popular belief, a MIDI (Musical Instrument Digital Interface) file contains no actual recorded audio. Instead, it is a set of digital instructions—think of it as a player piano roll. It tells a synthesizer or sound card which notes to play , when to play them, how loud to be, and which instrument (piano, drums, strings, etc.) to use.
: Because they are data instructions rather than fixed recordings, you can change the tempo or key instantly without distorting the sound quality. midi karaoke zip files