" The louder a person speaks in an assembly the more attention he attracts and all those present perforce give him a hearing. In the same way, if a Sufi sends forth the vibrations of his thought and feeling, they naturally strike with a great strength and power on any mind on which they happen to fall. As sweetness of voice has a winning power so it is with tenderness of thought and feeling. Thought-vibrations to which the spoken word is added are doubled in strength; and with a physical effort this strength is trebled. "

― Hazrat Inayat Khan , The Mysticism of Sound and Music