Ouranis was the Muse of Astronomy. Pythagoras understood the Muse-ic created by the mathematical relationship between the order of the planets, and, according to Aristotle thought that the movement of these planets must produce a sound. Flash forward to Alba Mundi, the sound of the planets at http://www.pianopianoforte.com/piano_music/piano_music_english/the%20sound%20of%20the%20planets.html, if you want to hear what this music sounds like.