DIY Electronic Musical Instrument
Digital audio.
Code can be changed
https://www.pjrc.com/teensy/gui/index.html
The sounds are generated by a Teensy 3.2 / 3.6 / 4.0 + audio shield.
This is a controller circuit; eight knobs.
A pocket sized version of the Drone & Drama instrument series.
https://github.com/bjc01/Drone_Drama_v2
https://www.thingiverse.com/thing:4598555
https://www.thingiverse.com/thing:4616446