The answer is a play based on the lives of the saints. Usually instrumental music, played between sections of a work. In sacred music, interludes are often improvised passages in the organ, between the verses of a hymn or a psalm. In stage works, especially in opera, interludes are played between scenes or acts and usually serve to advance the action of the drama. The term is also used as the title of a musical work without any of the cited connotations.