Watch the balls bounce on the piano keys to make strange music. Click and drag any key to a new position for different musical effects. Click Rebound/Through icon to change how the balls interact with the piano keys. Rebound makes the balls bounce off the keys, whereas Through lets the balls pass through the keys. Click on the number icon to change the number of balls in motion. Click on the background to randomly change the direction of the bouncing balls. Download and modify this project and make your own music machine! Enjoy.