This video shows a clever modification to the Thingamagoop: a lightproof cardboard enclosure with a cardboard strip to control the amount of light reaching the photocell. You control the synthesizer’s pitch by moving the cardboard strip. Maker Pete Ashton posits:
In theory a pianola-style score could be written on a long strip. That would involve working out the pitch differences between various sized holes. But it could work.
In the Maker Shed: