Here's a video of me playing around with gnome shell javascript stuff. I made all windows "bump" to a certain rhythm. I think in one version I was able to "program a beat" by clicking or hitting a button, and having it loop that pattern. It looks pretty shaky in the screen capture I took, but it was fairly smooth in action. It has a nice 3d-ish effect, each window (as well as the desktop) was bumping independently. It would be a cool thing to interface with a media player that could measure BPMs of the song playing.

There's not much point providing the source (though you can see some of it in the video) because it's works for a version of Gnome Shell that was already out of date by the time I was writing it, to say nothing about today.