Using a circuit we found online, we have successfully made a voltage controlled oscillator. However, we found we need higher voltages than we can pass through the Arduino (-16 V to 16 V range). Whoops.
We laser cut our first overall structure and it fits well!
We determined the dimensions and spacing of the mechanical pulley system that will move the cylindrical blockers.
We finalized the dimensions of the CAD and bought a copper pipe! We then laser cut the box and started to fabricate the keyboard structure as well. We also iterated on the user input levers for a more ergonomic shape as well as adjusting the hole so it could spin freely on the dowel.