Pittsburgh's pianist Mary Lou Williams (1910) was the most innovative composer of the
Kansas City school. She mainly wrote for Andy Kirk's big band, Twelve Clouds
of Joy, where she played piano:
the bluesy Froggy Bottom (november 1929),
Cloudy (november 1929), Mess-A Stomp (november 1929),
the boogie-woogie Little Joe From Chicago (february 1938),
the subversive Walkin' and Swingin' (march 1936),
and Scratchin' In The Gravel (january 1940).
After she retired from jazz, she composed
a Duke Ellington-inspired Zodiac Suite (december 1945) for an 18-piece orchestra,
the cantata Black Christ of the Andes (november 1963), and the Mary Lou's Mass (completed in 1970).
Williams died in 1981.