Simple web app for visualising music notes/chords as combined sound waves.

Click notes to combine waves. Click again to deselect.
Use mouse scroll on wave to zoom in/out.
Click the wave to play the note(s)/chord. Warning: start with your speakers on low volume!

Further ideas:

• Display the total wavelength, approximately where the pattern of the combined notes repeats?

For my reference:

// Black key position generator

for (var i = 0; i < 100; i++) {
    var mod = i % 7;
    if (mod !== 2 && mod !== 6) {
        console.log((i+1) * 54 - 19);
    }
}

Thanks to Pedro Ladaria for the audio library at http://codebase.es/riffwave/