DoodleChaos's Line Rider compositions
Line Rider is an old game where you draw lines and then see if a character can sled down them using basic physics. Like all these things it's been appropriated by people with a bit too much time and somewhat divergent brain chemistry with delightful results to sync the routes with music.
I particularly like those done by DoodleChaos which are particularly inventive. They're nice because while they don't work like musical notation at all they look like they might, lulling you into a sense that the rider is creating the music somehow. But mostly they just tap into the same warmfuzzys as the music synchronisation in Baby Driver.
(No spoilers in that clip)
DoodleChaos also has a really nice line in 2D Rube Goldberg machines which, of course, sync to music. This is quite something and the ending had me sniggering out loud.