Nobumichi Tosa is the founder of Maywa Denki is a Japanese design firm that creates wonderful nonsense gadgets, like this musical backpack that makes music when you move your arms.
As you can see, different positions correlate to different types of sounds and tempos. There’s no explanation provided for how the machine works, but that’s completely unnecessary. It’s a nonsense machine, after all.
[Maywa Denki via Dezeen]