Thanks to Michael Matteo for pointing us in the direction of this YouTube video showing a fidget spinner as an integral component of a modular synth.
The video's poster had this to say, "I saw a post online where someone took a fidget spinner and made a synthesizer module with it. I decided to try that myself on my own homemade synthesizer. After I built the module, I tried it out by making a quick dubstep-ish patch."
Revisions that turned synths into brand new machines