[mrcoles]

Each note is generated as a separate sound file when the piano first loads. They're all short wave files. So when you hit a bunch of notes at once, it's just playing several sound files at once.

If you click the square in the upper right, you'll get options to change the waveform and volume response. There are some other options too, like shifting by an octave or changing the color of the piano :)

Better things could be done by using the web audio APIs, but I explicitly started this project wanting to build audio using data URIs.

[tantalor]

Could you improve the loading performance by precomputing the wave files? I'm thinking you could slam the data URIs together in a compressed blob.