An exploration of musical harmony from its ancient fundamentals to its most complex modern progressions, addressing how and why it resonates emotionally and spiritually in the individual. W. A. Mathieu, an accomplished author and recording artist, presents a way of learning music that reconnects modern-day musicians with the source from which music was originally generated. As the author states, "The rules of music--including counterpoint and harmony--were not formed in our brains but in the resonance chambers of our bodies. " His theory of music reconciles the ancient harmonic system of just intonation with the modern system of twelve-tone temperament. Saying that the way we think music is far from the way we do music, Mathieu explains why certain combinations of sounds are experienced by the listener as harmonious. His prose often resembles the rhythms and cadences of music itself, and his many musical examples allow readers to discover their own musical responses.