The Greeks had it figured out. About music that is.
Music was thought to be born of the Gods. People thought music had magical powers. It was said to heal sickness, purify the body and mind and work miracles in the realm of nature. If you think about it that isn't to far off from the Old Testament story of David and Solomon when he played his harp and cured Saul's madness.
Music had a wider meaning for the Greeks. It was inseparable with numbers, which were thought to hold the key to the whole spiritual and physical universe. So when the sounds and rhythms were organized, it exemplified the harmony of the cosmos and corresponded to it. Plato expounded this theory in the Republic.
In fact, most of the important Greek thinkers associated it with the Cosmos. Mathematical laws corresponded both the underlying system of music and the stars and planets. Therefore, each planet was associated with different modes. Plato wrote of this correspondence in "The music of the Spheres" - the unheard music produced by the revolution of the planets.
It is interesting to note that as science progresses, scientists are discovering that everything has a "pitch” Even string theory supports this notion. The notion that all things are made of the tiniest of tiny 'strings' that vibrate and, in a way, form a kind of harmony, creating structure to all matter.
Recently, the universe was said to have the pitch of a Bb.