Demo of my app pianoply (pee ANN uh plee), which runs in a web browser and uses a digital piano/midi controller keyboard, allowing you to play karaoke style on top of original music videos. Or you can run it without a keyboard attached, and it can function as a music visualizer that passively teaches you how music works. Hoping to connect it to NodeTube. Currently it relies on YouTube but it should be able to use another video hosting service.