A profound exploration of the simple numerical ratios that underlie our solar system, its musical harmony, and our earliest religious beliefs. As modern humans first walked the Earth roughly 70,000 years ago, the Moon's orbit came into harmonic resonance with the outer planets of Jupiter, Saturn, and Uranus. The common denominators underlying these harmonic relationships are the earliest prime numbers of the Fibonacci series--two, three, and five--the same numbers that interact to give us the harmonic relationships of music. Exploring the simple mathematical relationships that underlie the cycles of the solar system and the music of Earth, Richard Heath reveals how Neolithic astronomers discovered these ratios using megalithic monuments like Stonehenge and the Carnac stones. He explains how this harmonic planetary knowledge formed the basis of the earliest religious systems, in which planets were seen as gods, and shows how they spread through Sumer, Egypt, and India into Babylon, Judea, Mexico, and archaic Greece. Revealing the mysteries of the octave and of our musical scales, Heath shows how the orbits of the outer and inner planets gave a structure to time, which our Moon's orbit could then turn into a harmonic matrix. He explains how planetary time came to function as a finely tuned musical instrument, leading to the rise of intelligent life on our planet. Heath seeks to reawaken humanity's understanding of how sacred numbers structure reality, offering an opportunity to recover this lost harmonic doctrine and reclaim our intended role in the outer life of our planet.