Topic: how was this done The Lamb Lies Down on Broadway

this is a brilliant tune very difficult, even though it was done by ear, its all music, notes, chords, riffs, repeating phrases, etc,   the video example of this tune shows a guy pushes buttons in the exact order how the song goes, but the comment and or question is what is the music behind the buttons, it this saved as a program? or as a file?  there must be some sort of sheet music, or music that can be writtten down for it?? thanks