This project was inspired by famous YouTube pianist Rousseau. In his videos, Rousseau plays beautiful piano pieces that are accompanied by visualizations of the notes on the keyboard itself. Evening thought that would be helpful in learning how to play the piano, and so he set out building his own visualization system. That is made from a strip of Adafruit NeoPixel-style individually-addressable RGB LEDs that runs the entire length of the keyboard and is controlled by a Raspberry Pi Zero W.
The Raspberry Pi receives MIDI data via Bluetooth from Synthesia software that’s running on a tablet. That software connects to the keyboard and shows the notes to be played as you play them. Normally those notes are just shown on the screen, but Evening’s setup also lights up the LEDs on the keyboard itself. Blue lights indicate the left hand finger positions, and green lights the left. The software automatically waits until you’ve pressed the correct keys, which makes this a fully-interactive way to learn to play the piano on your own.