I built a machine that plays songs by popping bubble wrap. pic.twitter.com/43dTrxPPB7
— Simone Giertz (@SimoneGiertz) August 12, 2022
This doesn't even count among Simone Giertz's wierdest inventions, like her toothbrushing robot or her proud parent robot.
Popping bubble wrap is fun, but it's also a force that can be controlled and distributed. The puff of air that comes from the popped bubble can be channeled into a tube, which will play a note. Grouped together these tubes form a pan flute. To play multiple notes in rapid succession, you need to mechanize this process like a music box with a barrel containing adjustable pegs to pop the bubbles precisely.
That's the concept stage. The implementation stage took much, much more effort because getting the bubbles to pop reliably and the sheet of bubble wrap to stay aligned required a lot of redesign and precision engineering. You can see Giertz's 15-minute build video here.