Rok, I've been comparing "Mary Lou Williams" to "Bird". Not to "Bird" personally but to his era and beyond. One of the reasons I'm doing this is because I was so late in discovering Mary Lou. Since she came from the swing era, I assumed her music would reflect that fact; Tommy Dorsey, Benny Goodman, Earl 'Fatha' Hines, and Duke Ellington. As famous as those people are, they are not my cup of tea; more my parents cup of tea. That's why I define music "Before Bird", and After Bird; BB and AB. "Bird" revolutionized jazz, and that's an undeniable fact.
My point is that Mary Lou Williams was so advanced that her music is more akin to Birds music than to the swing era. Let's compare her "It ain't Necessarily So" with Miles take on the same tune.
https://www.youtube.com/watch?v=z4THBVc47ug
Although she came from the swing era, this is as hip as it gets. She's got just the right touch. Next the same tune by Miles
https://www.youtube.com/watch?v=A-EgyUcHSSQ
Before we discovered Mary Lou Williams, I thought Miles's was the hippest version of that tune, but now I'm not so sure.
Any way you look at it, she was incredibly advanced, and I still can't figure why I'm so late in discovering her.
Enjoy the music.