I wanted to share a project we recently made - my part was EMG interpretation and LED patterns. Since it has no particular purpose, I guess it falls under "Art" category 
In its core there is a ESP32 which receives data from uMyo muscle sensor via BLE, and generates trains of pulses, with intensity proportional to muscle activity. It also kinda reacts to orientation - but the code had problems in the first version and it's not visible there. Then we made a second iteration of patterns:
-- in this version muscle intensity controls pattern intensity (LED brightness in rainbow mode, and sparks frequency in sparkling mode), arm elevation switches between mode, and arm rotation "rotates" rainbow, and changes color of sparks