Sound has the capacity to affect us on all levels--physical, emotional, mental and spiritual. This work ties together a number of traditions, both scientific and metaphysical, to explore the beneficent force of music. Drawing upon research into mathematics, chemistry, physics and ancient cultures, the author explains the healing effects of different instruments, keys and musical forms. She explains which keys stimulate specific areas of the body that govern the immune system, excite the passions, or soothe the soul. She also interweaves traditions as far-flung as Native American beliefs and the Chinese meridian system, the properties of Chakras (from the Sanskrit word meaning "wheel") and their correspondences with Western nervous and endocrine systems.