Most unusual/mesmerizing female voice.

Patricia Barber......how does she hit those high notes?
Joan Baez........HAVE to give her a nod.
Edie Brickell.....always enjoy her.
Tori Amos..........Yup!
Natalie Merchant........have to second that vote!
Janis Ian.......don't know about unusual but can she sing!
Kate Bush.........gotta love her voice.
Sandy Denny.........A big hats off to the only female vocalist to accompany Robert Plant!

Oh, here's one for the list.......ZHU Zhe-qin
Google her album, Yellow Children.