More female vocals

If you like Etta I would look into Lorez Alexander - big voice and lots of attitude like Etta, also Cassandra Wilson (her cover of Van Morrison's Tupelo Honey is excellent), Salena Jones, and Jacintha are all very interesting voices with great takes on their own music as well as the classics.

sorry spelled a name wrong - Lorez Alexandria - I cut my teeth on her album Alexandria The Great.

Sarah Brightman and Whitney Houston.

Melody Gardot--one of the best singer/songwriters I've heard in the last decade.

I assume you already have Eva Cassidy, “Live at Blues Alley.” If not, that should be your next purchase.