Wikipedia : This day (May 28, 1981), in Durham, North Carolina, died Mary Lou Williams, an American jazz pianist, composer and arranger.
The Mary Lou Williams Foundation : . She became an early champion of bebop, adapting its modern harmonies and rhythms to her blues and boogie rooted piano style. In the ’50s she had a spiritual crisis that led her to abandon music for about three years; she became a Roman Catholic.
@allmusic : Although for decades she was often called jazz’s greatest female musician (and one has to admire what must have been a nonstop battle against sexism), she would have been considered a major artist no matter what her sex.
@last.fm : She became a professional musician in her teens. In 1930, she joined Andy Kirk’s Twelve Clouds of Joy, of which her first husband, saxophonist John Williams, was already a member, and became the band’s leading soloist, composer, and arranger.