Thanks. I was thinking of Nina Simone but couldn’t remember her name. I remember when she died a year or two ago our local NPR station had one of their music shows dedicated to a look back at her music, and my wife kept asking me “Are you sure that’s a woman?” 
Angela Gossow should qualify, as one of the few female extreme metal singers.
Put me in for Tracy Chapman, too. I still mistake her voice for man’s from time to time, even though I know it’s her singing.
If we can go Brazilian, the mighty Maria Bethânia.
Oddly enough, the first time I heard her band, Arch Enemy, on the XM metal station, I thought to myself, “damn, if that doesn’t sound like a female Cookie Monster.” When I got home I Googled the band and found out I was right.
There’s just a certain quality to her singing that rounds the edges off the typical death metal “grunt”, and makes it a bit more pleasing to the ear (or less displeasing depending on your view).
I’m actually switching my answer Allison Moyett. Chapman sounds just as much like a male, but Moyett actually sounds like a guy with a lower voice singing higher.
Allison Moyett, for me. I recall the old joke that Kim Carnes and Rod Stewart were actually the same person 
I think the poster you were referring to was simply listing all the lesbian singers (s)he could think of.
Joan Armatrading can sing pretty low but I don’t think of her voice as particularly masculine.
Yma Sumac could sing a true baritone.
Yma Sumac could sing *anything *- she was Yma Sumac ;).
I tend to go with Alf (Alison Moyet) - she not only gets low, but she can put an edge on her voice like she means it. When she growls “Didn’t I Bring your love down?” the only response is “yes, ma’am” 
Both Tracy Chapman and Natalie Merchant drive me crazy: both have great-sounding voices, but never sing outside maybe a 5-note range (I am exaggerating, but not by much) and never. push. their. voices. They sing basically flat emotionally - for Chapman’s first hit, Fast Car, it worked because the lyrics have a resigned stillness to them that really suits her approach. But Natalie Merchant’s cover of Patti Smith’s Because the Night? Please - one wants a knock-down, drag-out round of The Nasty, and one is looking for some Kenny G and white zinfandel…
I find Natalie Merchant “pleasant” and yes, I mean that as an insult.
But my personal pet peeves aside (she’s bland, I tell you - bland!!) I go with Alison for both her timbre and delivery…
I would never really have picked Etheridge or Indigo Girls - lesbian != mannish-sounding to me, necessarily…
I don’t think Etheridge sounds like a man because she’s a lesbian. I think she sounds like a man because she has kind of a deep, raspy voice.
I mean, KD Lang is a lesbian (right?) and I don’t think she sounds like a man.
Ahem. The Boss’s.
It was co-written, and she released it first…
Patti delivered the heat I was referring to in my earlier post; that was all that mattered. Yes, I know the history of the song…
I remember being stunned after hearing this song that this PJ Harvey person was a woman. She sounds a lot more feminine in every other song I’ve heard by her since.
And after listening to this cover of Coventry Carol that Christine McVie was one of the women in Fleetwood Mac.
I can’t link to a clip at the moment, but how about Q Lazzarus, singer of “Goodbye Horses,” better known as that song from The Silence of the Lambs?
I was really surprised when I found out a woman was singing that song, instead of a man with a higher voice.
Marlene Dietrich
“Sweet dreams are made of this / Who am I to disagree…”
WTF. I am living a sheltered life.
For sheer depth of voice, I’d go with Cassandra Wilson, but she doesn’t sound masculine all the time.
When I was a teenage boy, I thought my voice sounded a bit like Tracy Chapman. I haven’t maintained my voice well, so it’s probably lower & rougher now. But yeah, Tracy Chapman was a good call.
And of course I originally thought Melissa Etheridge was a guy–or rather that one of her songs was sung by a guy–lots of rock tenors that sound like her.
Funny, I remember being surprised to hear that “Go Your Own Way” wasn’t sung by McVie, but that wasn’t because of thinking that McVie sounded like a man.