Plink is a fun web app, that allows you to easily make music with the click of a mouse.
The colour is your instrument, the height is the pitch, click to make a noise and that’s about it. You don’t have to be at all musical, as all notes played will be in time and in tune. You are supported in your musical creations by a simple regular kick drum and other players around the world.

Have a go here. Careful, you may find yourself spending hours aimlessly clicking away!