A couple of other mechanical noise makers.
Stepper motor music for Benny.
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An “Organ” with steppers used ad pitch transducers
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— Other Stepper motor music examples —
“Megalovania” (Undertale) - Played on 31 Stepper Motors
(The Trinamic Stepper Driver Chip which magically takes the noise out of 3D printers, doesn’t have a musical byproduct.)
Single RC servo doing a rhythm track
(Like that guy attempted with cell phone buzzers, when your phone accesses this page)
Here’s a board that drives 16 servos from MIDI (but not in a musical way)