Looking for good recordings of female vocals I have not yet tried...

Saw no mention of...

Rhian  Benson

Carly Simon

Valerie Carter

Rita Coolidge

Judy Tzuke

Some great stuff here, grooving to Linda Ronstadt and Sophie Zelmani.  Don't think I saw any mention of Joan Baez, great acoustic folk or with a band in the '70s.  Also love Aimee Mann, such a great songwriter.

And in the guilty pleasures category, there's Barbra Streisand - Guilty, a vocal classic, great big belting.  Just picked up The Story of My Life: Lea Salonga Live from Manila, her voice is just clear as a bell and so emotive.  And was rocking out to Evita recently with Patti Lupone, powerful as well and such a great actor, a shining performance.

Patricia Barber (too rich for my blood)

Simone Kopmajer -- Taking a Chance on Love ("Don’t Let Me Be Lonely Tonight")

Jacintha -- Here’s to Ben

https://www.youtube.com/watch?v=yS69mWUgotw

For great SOUNDING recordings of female voice, you gotta hear the Acony Records LP’s of Gillian Welch. They also fulfill your request for "mainly acoustic", non-"loud electronic" music.