This is beautiful. It would be amazing to have the tracks encode/decode audio, you know? Like, the track of the marble can be used to generate different frequencies...
I actually attempted this, the idea of a python script that converts a midi track into a marble run is just too good to not try. I printed a large drum with different track structures inside so I could test various "slopes" by changing the speed and it just doesn't work, the balls bounce around too much to get an audible pitch. A less rigid material or a larger bearing would likely work better but I decided to focus on getting the normal version working well.
Maybe at the bottom your marbles could land on surfaces with different accustic properties. Track selection would determine the surface and release time would determine the timing.
