harmony of the spheres

harmony of the spheres or music of the spheresa Pythagorean concept (see PYTHAGORAS), harmony having cosmic significance for the Pythagoreans. It seemed to them, as to others, that the heavenly bodies (the spheres) must, like other large bodies moving at speed, produce a sound as they whirl through space, and that since the bodies move at different speeds they must each produce different (but harmonious) notes. Plato's version of this idea, expounded in the Myth of Er (Republic, book 10), is that on each of the eight concentric circles in which the bodies rotate stands a Siren uttering a note of constant pitch, the eight notes together making up a scale. Because the sound is with us constantly from birth and there is no contrasting silence we are unaware of it.