Niklas Roy hat in in Wrocław (Breslau), Poland, a huge, up to amplifiers, built entirely mechanical machine, the generative per crank control Music (A pair Samples on SoundCloud) created. More images, GIFs and Info there is here

The Music Construction Machine is a large, Public, generative music box, which people can operate via a big hand crank. The project is on public display in the Goethe-Institut Pop Up Pavillion in Wroclaw, Poland, as part of the cultural capital program. […]

the music is generated by an algorithm, which is implemented entirely in mechanical hardware, and which iterates through all kinds of possible sequences of beats and tones. Thus, the machine permanently ‘constructs’ new ‘music’ while it is being operated, hence the name “Music Construction Machine”.

Although the hardware determines which tones are played, the operators still have a strong influence on the interpretation and expression of the music, as they can decide how fast they crank and where they interrupt the flow of music.

Nails