Synthesia loosely follows the Guitar Hero format — music tracks appear visually on screen, and your challenge is to play the correct notes on a keyboard. Unlike Guitar Hero, however, Synthesia actually helps you learn how to play music using a real MIDI keyboard and MIDI song files. Several MIDI songs are included, including popular themes from video games. More are available from various sites on the Internet.
You can practice left-handed and right-handed parts separately and slow songs down if you’re having trouble with particular parts. There’s also a scoring component that judges you on accuracy and speed.
Once you’ve loaded in the MIDI track you want to play, you tell Synthesia which instrument or instruments you want to play, then click on the Play Song button, and the game begins.
The game is actually a bit more Mario Teaches Typing than Guitar Hero, but it’s free and it’s for keyboardist so give it a try and if you like it consider giving the author a bit of PayPal love.