The Pythagoreans held that the distances and motions of the planets correspond to musical ratios, producing a harmony we do not hear because we have heard it always. Plato’s Republic ends with the sirens singing on the spheres. The idea endured through Kepler.
Harmony of the spheres
The Pythagorean idea that the heavenly bodies move in mathematical proportions that make a celestial music.
Also: music of the spheres