Phew, the Song of Silence don't seems to be John Cage's 4'33"!^^
It's a really nice game. I like its musical sound-design. The association of light and music works pretty well. It's not finished yet, but it has a charming universe already.
An issue I should mention: at the beginning of the game, I felt into the first hole and found myself stuck below, unable to jump back up or to fall below. I played with the itch app, maybe this had an influence on the physics.
Anyway, congrats for making this game!