This is excellent. The graphics and sounds are nicely done. One thing that I don't see in it, but that I find fascinating, is that in western music each half

This is excellent. The graphics and sounds are nicely done. One thing that I don't see in it, but that I find fascinating, is that in western music each half step represents a ratio of the twelfth-root of two, in terms of frequency. That way 12 half steps (an octave) will double the frequency. Certain notes within this are close, but not exactly, on a "simple ratio". It's just coincidental that it works out pretty good. (although you could make it work out just as good with something other than a 12 step scale....a 19-step scale has been used: https://en.wikipedia.org/wiki/19_equal_temperament https://en.wikipedia.org/wiki/19_equal_temperament ) Anyway, I think that would fit in well with what you've done so far, but obviously, explained in the nice simple graphics that you seem very good at. I also must say I love the way you use color, I have a music project of my own (that I'm hoping to debut very soon) that also uses color in a very similar way. Did you know that Isaac Newton fixated on 7 colors (ROYGBIV) because he thought there was a connection between the diatonic scale and colors? That's why indigo seems to have been promoted from some obscure color to one of the "basic" colors of the rainbow. (I prefer BOYGBPP, red-orange-yellow-green-blue-purple-pink)