sacred music places her in the rarified company of Duke Ellington.
Her music combined two important themes of the times. Mary's faith
was formed (and complemented) by the post-Vatican II upheaval in the
church and the civil rights movement. She prevailed upon Father Woods
to write lyrics for her first sacred work, Black Christ of the Andes,
in 1962. It celebrated St. Martin de Porres, a seventeenth-century
Dominican lay brother and the first black canonized by the Roman Catholic
She was the guiding spirit behind a February 1967 concert at Carnegie Hall, entitled "Praise the Lord in Many Voices." That spring, Mary briefly returned to Pittsburgh, where her sister lived, and composed her first Mass, known as The Pittsburgh Mass. She wrote Mass for the Lenten Season the following year.
Williams returned to Europe in late 1968. Her hopes to perform Mass for the Lenten Season during a Mass at the Vatican in February 1969 in honor of Dr. Martin Luther King were dashed by church officials, who
|| objected to use of drums in the composition. In March 1969, Msgr. Joseph Gremillion, secretary of the Pontifical Commission on Justice and Peace, commissioned Mary to write a Mass using texts for the Votive Mass for Peace, known as Music for Peace. In 1971, the great choreographer Alvin Ailey reworked elements of that work to choreograph dances of praise, which he called Mary Lou's Mass. Williams' earlier disappointment in Rome was alleviated to a degree when she performed Mary Lou's Mass at St. Patrick's Cathedral, on February 18, 1975. The first jazz played during Mass at the New York cathedral included a 60-voice youth choir and concluded with spontaneous applause that transformed the solemn proceedings.
Since 1996, two Ph.D. dissertations and one master's thesis (all in the collection of the Institute of Jazz Studies) explore this aspect of her work. Mary Lou's Mass was performed in concert in the National Cathedral in Washington in March 1999 and by the Cleo Parker Robinson Dance Company, an African-American troupe in Denver, in September 2000.