Synthesia - A fun way to learn how to play the piano.
Guitarix - Guitarix is a simple Linux Rock Guitar Amplifier for https://alternativeto.
Playground Sessions - Online piano learning game.
Rakarrack - Rakarrack is a richly featured multi-effects processor emulating a guitar effects pedalboard.
Piano From Above - Piano From Above is a program that turns learning the piano into a videogame.
ToneLib GFX - The perfect custom tone with a complete guitar studio in your computer