Google's Chrome Music Lab has fun simple instruments to make pleasing sounds

These 12 musical "experiments" let you make and tweak pleasant sounds.

Chrome Music Lab is a collection of experiments that let anyone, at any age, explore how music works. They're collaborations between musicians and coders, all built with the freely available Web Audio API. These experiments are just a start. Check out each experiment to find open-source code you can use to build your own.