How Mary Lou Williams Shaped The Sound Of The Big-Band Era

"The greatest woman jazz pianist in captivity." "The greatest woman jazz pianist in the world." "Highly acclaimed as a deluxe tickler of the ivories." "One of the foremost swing pianists of either sex." By 1936, then-25-year-old Mary Lou Williams' reputation already preceded her. The pianist's primary gig — Kansas City band Andy Kirk and His Clouds of Joy — was taking off, booked for packed dances around the country alongside artists like Louis Armstrong. Williams was the group's marquee attraction, a little for the novelty of a woman pianist but mostly because of her undeniable artistry — one critic, for example, questioned whether Art Tatum could really swing like Mary Lou Williams, with no caveat in sight. She'd even already garnered enough acclaim to record solo sides.

But Williams' remarkable, prescient playing with the Clouds of Joy was only part of the explanation for her and the band's success. Her arrangements for the group, which she'd started contributing at age 19, helped spark their national breakthrough —