Joncas provides a succinct, 115-page analysis of nine official statements—produced by papal, conciliar, curial, and bishop’s commission initiatives—on the role of music in worship. The book discusses the role of music in worship, criteria for evaluating music, the role of musicians, and the role of instrumental music. The author's analysis provides a way to understand the development of Roman Catholic thinking about music’s purpose in worship—a development that has many parallels in Protestant denominations.