Book excerpt: The seven vowels which we use every day in speech depend on the phenomenon of harmonics which is at the very basis of music. When we hear vowels we are hearing the laws of harmony which are ultimately the laws of number that are said to govern the universe. This is the first book on the subject to appear in English and brings together the fields of linguistics harmony, mythology, history of religions, and occult philosophy. Scholarly, yet practical, this book gives instructions for discovering one's own healing, centering, and uplifting tones.