Following her conversion to Catholicism in the 1950s, Mary Lou Williams’ main goal for her musical life was to merge her two churches: the Catholic Church and the church of jazz. The compositions that culminated in Mary Lou’s Mass were her attempt to prove that jazz could be a form of religious music. (Williams herself simply called it “music for the soul.”) While she wrote several versions of “Mass” in the '50s and '60s, the final product came about when choreographer Alvin Ailey invited her to collaborate on a production based on religious music. The resulting album is astonishing. It incorporates a full range of music from the African diaspora and American spirituals to Latin music to funk. The results attain Williams’ goal of achieving deeply reverential music that also spoke to the shared history and struggle of displaced Africans. The music likewise acknowledged that dance was itself a form of religious expression. Even though he doesn’t appear on the recordings, Ailey’s participation can't be overstated. This is music driven by the beauty and ecstasy of bodies in motion.