This book is a study of religions in the history of American jazz, and of jazz’s contributions to American religions. Going beyond extant biographical studies of individual exemplars, or cursory attention to either “spirituality” or jazz in the civil rights movement, the book argues for the centrality of religious experiences to any legitimate understanding of jazz, while also suggesting that attention to jazz opens up new interpretations of American religious history. Focusing on the outer reaches of its key categories, “religion” and “jazz,” the book explores jazz in specific religious traditions, musical histories of American culture and religion, religio-musical communities, improvisational ritual, jazz and meditation, and even metaphysical systems. The book links the music’s visionaries (from Duke Ellington to Anthony Braxton, among dozens explored) to those of American religions (from Madame Helena Blavatsky to Elijah Muhammad). It situates jazz’s communities like the Association for the Advancement of Creative Musicians in a history of religious experimentalism populated by the Transcendentalists and the Shakers. It listens for the resonances shared by jazz’s ritualists and practitioners of Santéria, Pentecostalism, or Qi Gong. The book connects religious studies to jazz studies through thematic portraits, historical setting, thick description of the music, and a vast number of interviews to propose a new, improvisationally fluid archive for thinking about religion, race, and sound in the United States.