How women, both American and internationally, have affected jazz.

Moving over to one of my favorite places for jazz, Brazil, I must mention the great Flora Purim. She uses her voice like an instrument, often immersing herself in abstract jazz. I have purchased her album "Encounter" several times because I keep wearing it out.

@stuartk 

I think all music must be from the head and heart, but some lean more one way and some more the other way. Music that you must sit down and listen to with concentration is more heady. Music that makes you want to get up out of your chair and dance is more hearty. Sometimes I prefer one and sometimes the other. Then there is spiritual music which fills the listener with a kind of joy that balances between the head and heart. 

Lot of great women mentioned here. It got me to thinking about the many excellent female artists I've had the very good fortune to see/hear live over the years. Folks familiar with the SF Bay Area will recognize of few of these venues.

In no particular order:

Betty Carter, at the Greek in Berkeley. Also, an accomplished educator and innovator. 

Alice Coltrane, Berkeley Community Theater. @audio-b-dog mentioned her as well. I don't remember if Pharaoh was with her. Kind of an out of body experience. 

Carmen McCrae at the Palo Alto Jazz Festival.  She could create intimacy with a large gathering. 

Casandra Wilson, Kimball's East (anybody remember that place?). Great acoustics and talk about Casandra's stage presence and powerful, sultry voice. 

Diana Krall, Stern Grove. I too have great admiration for her musicianship. She was so casual and disarming. I went down close to the stage when she came out to do a sound check. Got back to my seat, and my wife says, "What are you...  some kind of groupie?!" 

Diane Reeves, Zellerbach Auditorium. She let you know she came to entertain... have some conversations, sing, and tell stories through her lyrics. 

Nancy Wilson, The Circle Star in Redwood City. Jazz vocalist royalty in my opinion... a truly elegant lady. I love her recorded stuff in front of the Johnny Mercer orchestra.

Adding to the list, a couple more. I'd have to say Esperanza Spaulding. She's an amazing bassist and gifted singer! Very creative.

And last, here's one  you might not associate or think of when it comes to jazz. Amy Winehouse. She grew up on Sarah Vaughn, Billie Holiday, and Dinah Washington. It shows up in her earlier "pre-fame" music. Tragic life... she really had a gift. 

Rachelle Ferrell, wildly unknown to many, with a scary good monster of a voice.

Even though Erykah Badu is considered a neo soul artist, her voice is so stunning, she can sang jazz with the best of them. Her voice is very Billie Holiday-esque without being a copy, that is all her own.

And speaking of Brazil, the incomparable Elizete Cardoso whom of which I adore.

For those who think of Patricia Barber as just a singer, listen to her piano playing on this number. She is skilled and unique: 

https://www.youtube.com/watch?v=6Q9Gi8LjMyI