This is a three parts synthy, combining the following
Drones
always on when turning (probably 40106)
Melodic keyboard
needs a keyboard of some sort
rhythm
with input from dynamo or encoder wheel on crank
will also need a good generator / dynamo - 3 phase brushless maybe?
I didn't say this yesterday, but I'm very happy to see a hurdy gurdy project on here. It's been the instrument I'm most interested in learning (though that interest is still not enough to actually do something about) since I saw Guilhem Desq's Omen video 3.75 years ago. I have an idea for a musical project that I might work on soon, and drones might be a great addition to it, so thanks for the inspiration there!
Another idea: droning drone! A drone (the flying kind) that produces a controllable musical droning sound as it flies.