The few I will add
older
Abby Lincoln
Her version of Afro Blue is fantastic if you can find it.
Joni Mitchell
Carole King
newer
Jenny Lewis
She is in the band
Rilo Kiley. She also did a solo album and one with the
Watson Twins.
Her album with the Watson Twins has a Dusty Springfield feel to it.
Amy Millan with her
solo stuff and with her band
Stars.
Maria Taylor another favorite female singer/soloist.
*I know Emmylou Harris has been mention but I just wanted to add my favorite song of hers. When she was playing with Gram Parsons and did
Love Hurts. IMHO it was the best version of the song hands down.
ok, rant off