Potwot is POssibly The World’s Only Torsional musical instrument. As an instrument it’s pretty minimal, with just a few notes available, made not for serious musical expression but rather as a demonstration of a concept. There have been no musical instruments that I know of, prior to Potwot, which are made for the type of oscillation known to physicists as torsional vibration — that is, oscillatory movement patterns based on twisting and untwisting motions (although there are a few other unusual instruments where torsional movement could arguably be said to at least play a role). Potwot is designed from the ground up to make primary use of these patterns. Plucking the end of one of the bent tines causes the base of the tines to twist and untwist torsionally, creating the vibration we hear through the pickup. In addition to the video linked below you can find more information on Potwot and musical torsionalism in this essay.