Joscelyn Godwin 
Harmony of the Spheres [EPUB ebook] 
The Pythagorean Tradition in Music

Professor of Music at Colgate University and a widely respected musicologist, Godwin traces the history of the idea, held since ancient times, that the whole cosmos, with its circling planets and stars, is in some way a musical or harmonious entity. The author shows how this concept has continued to inspire philosophers, astronomers, and mystics from antiquity to the present day.