CLASSICAL MUSIC ARCHIVES - CLASSICAL MUSIC
In a nutshell, MIDI is a digital protocol, that is, a language which communicates performance instructions for any musical instrument or device (such as your sound card) which understands the language. MIDI is not audio information. It is primarily used to communicate which, when, for how long, and how loud to play musical notes, and with which "instrument."
https://www.classicalarchives.com/midi.html#index
