A simple synth for the 201 Pocket Piano, lightweight enough that it can handle six voice polyphony.

– Knob 1 = sustain;
– Knob 2 = wave shape (square-ish to sine to pulse-ish);
– Knob 3 = release.

Image by Thomas Hawk: https://www.flickr.com/photos/thomashawk/2705771232/