Based in Amsterdam, the Error Instruments company is a tremendous source of electronic musical tools, with a specialty in the playful and the esoteric. Among its most recent is the Ballerina Eurorack, which puts the archetypal music box into the context of a modular synthesizer (complete with the ability for it to be impacted by control-voltage signals). And yes, the Ballerina is wound by hand. Naturally, the gadget plays a snippet from Tchaikovsky’s Swan Lake. If this is of interest, you might like other synthesizer implementations of old-school music boxes, as well as a synth-kalimba (or mbira), the African thumb piano.