The lecture series presented here, include "The Mysticism of Sound, " "Music", "The Power of the Word", and represent the harvest of Hazrat Inayat Khans lifelong cultivation of the transformative power of music and soundas much, at least, as could be rendered in words. For decades, these fascinating discourses have provided inspiration not only to Sufi practi- tioners, but also to musicians working in various genres. It is hoped that this new edition will bring Hazrat Inayat Khans spiritual philosophy of music to a new generation of divers for pearls in the ocean of the human heart.