I am a Bach fan. One of the master’s masterpieces is Das wohltemperierte Clavier. I stumbled on this website and it has a hidden gem in it. Hover over Bach’s picture and see the tracks popping up and scrolling. Click one and you’ll hear a few notes and the first few measures of the score. See it right top? “Play movie!”. The surprise is not so much the score running along with the (excellent) actual playing but the structure being displayed in moving colors.

Fugue No. 21: B-Flat Major Well-Tempered Clavier Book II