exceptional voices of female singers (non-classical)


What I'm talking about here is what critics of classical singing refer to as "the instrument": the exceptional beauty or uniqueness of the timbre of the voice qua voice.  For the moment, put aside preferences w.r.t. repertoire, interpretation, performance, style, delivery, etc., and just consider the *sound* of the voice.  We're *not* talking about favorite female artists here, because that kind of preference is based on a whole amalgam of factors.

I suspect some of the top figures in the category I've tried to define often aren't very popular among audiophiles, because of those many other factors.

My first three nominations: Barbra Streisand, Linda Ronstadt, Eva Cassidy.

twoleftears
Surprised so few mentioned the late great (sadly passed away long before her time): Eva Cassidy , who's rendition of Over the Rainbow blows away all others and that's starting with Judy Garland, Barbra Streisand , Judy Collins.......
Of course so much more there too. 
http://evacassidy.org/eva-cassidy-albums/
Linda Ronstadt rendition of "Blue Bayou" is awesome.
Dusty Springfield had such a unique voice its very sexual...

ozzy
The thing about Linda Rondstadt is that she has made her voice work in so many different styles--Mariachi, jazz standards, Gilbert & Sullivan, plus contemporary pop, folk, country, rock, blues, you-name-it.   Pretty amazing IMO