Lovely rPi project, and the guy also has some other really nice simple looking but super functional rPi projects like a little synth thing.

More:

https://www.reddit.com/r/raspberry_pi/comments/6ew1wd/raspberry_pi_loopersynthdrum_thing/ https://www.youtube.com/channel/UCCuskRipctoUWpAFSq02CQw