At the age of 16, in 1926, Mary Lou Williams was an accomplished jazz pianist. The evidence is on recordings she made that year. By 1930, when she became the permanent pianist in Andy Kirk’s band, she had synthesized the styles of James P. Johnson and Earl Hines into a way of playing that fit perfectly into the swirl of influences that were merging to form the Swing Era. Williams developed into one of the greatest jazz arrangers of the period. Later, she encouraged and was affected by the music that Dizzy Gillespie, Charlie Parker, and Bud Powell pioneered in the Forties. In My Mama Pinned a Rose on Me, she summarized the impact of the blues on her musical thinking and development. On two pieces, the singer Cynthia Tyson joins her. On others, the virtuoso bassist Buster Williams accompanies her. The previously unreleased bonus track "Syl-o-gism" is a stirring duet between the unrelated but highly sympathetic Williamses.