A female vocalist I feel has been sadly overlooked lately is Rebecca Kilgore. I first heard her a few years ago and she deserves much credit. However, I don't advise checking out to many You Tube videos because, as sometimes is the case, the quality of them leave a lot to be desired.
I 'strongly' reccommend checking out her CD's with tenorist Harry Allen, such as 'Live At Feinsteins'-a tribute to Billie Holliday, with some straight ahead tenor from Allen and a superb rhythm section. Harry Allen is the Webster/Young/Hawk/Getz and Zoot all in one. Plus, (don't run for cover) check the Film Musical treatment this gang give to the music on the CD's 'South Pacific' and 'Guys And Dolls' where they are joined by guitarist and mellow vocalist Eddie Erickson. Best check this out maybe on the 30 second excerpts on Amazon first. They swing this stuff like it has never be 'swinged' before!!
You won't be disappointed. If you are I promise never to darken this forum again!
Meantime this is one of the better video clips available. Rebecca seem to be reading the lyrics as she sings.
http://www.youtube.com/watch?v=MuskGJ8CNVY&feature=player_detailpage