Andy Belov has created a general-purpose programmable musical instrument.

With 18 touch sensors, a touchscreen, MIDI, and Bluetooth, it is intended as a blank canvas (or control surface!) on which to create new musical experiences.
Based around a Teensy 3.6 and Audio Adaptor Board, the device adds two custom PCBs and a fun enclosure to create a music-making device around the size of a handheld game console.

It can currently simulate a saxophone, flute, drums, trumpet, or steel drums. Source code can be found on GitHub, and demonstrations can be seen in the videos below.