Movie critics have racked their brains for years to come up with new adjectives to describe Kathleen Turner's voice, that raw, beautiful, smoky, inviting, seductive, husky instrument that helped make her a star with her first film role, as Matty Walker in Lawrence Kasdan's 1981 neo-noir Body Heat.

Femmes fatales don't come any more powerful than Matty, whose razor-sharp wits were every bit as dangerous as her curves.

Yet despite pleas from fans that she take up the mic, Turner has never applied that voice to a solo vocal gig.

Until now.

Turner, 63, will make her world debut as a cabaret singer Monday in Philadelphia in the appropriately titled Finding My Voice for a one-night-only engagement at the Philadelphia Theatre Company's Suzanne Roberts Theatre. She'll perform two sets, at 7 and 9 p.m.

Directed by Andy Gale and designed by Ed McCarthy, the show will create a full cabaret experience, with table seating and cocktails. Turner will sing an eclectic mix of songs chosen for the occasion, backed by a four-piece band led by Mark Janas.

The cabaret engagement marks a return for Turner to the Philadelphia Theatre Company, where she performed her one-woman show, Red Hot Patriot, in 2010.

What took you so long?
Part of it is that I was intimidated. When I came into the business 40 years ago — I'm now in my 40th year, I mean it's been 40 years! — every woman singer was a soprano, and so I thought, "This is obviously never going to happen to you." So, you know, I pulled back in my shell and I said, "No, no, I only act." This was for self-protection as much as anything else.

So no pop stardom for you. What about the stage: musicals, revues, sing-alongs?
That's the second thing: I didn't like musicals. I still don't like musicals. I never understood why people stop talking and break into song. It simply didn't attract me very much. So I just kept to singing with friends' bands, or I would sing a lullaby in a film.

What changed?
I really was never interesting in singing until the artistic director of Arena Stage in Washington, Molly Smith, asked me to do [Bertolt Brecht's] Mother Courage and Her Children [in 2014]. And it has five songs. My God, talk about a body of work in Mother Courage! My friends call it "Lear Squared." It's three solid hours where it could just as easily be told in three minutes.

So you said yes.
I said yes. And the best thing I thought I could do was first get the songs down. And I worked hard on those five songs with Andy Gale and Mark Janas so I could go on stage with confidence. … Well, I had such a great time, and the production was thrilling.

It was a turning point for you.
Yeah, so I thought let's keep this going and let's find out what I can do here. I went back to Andy and Mark and asked if they would work with me. We started to bring together songs that might work for me … songs that fit my body and that felt right and sounded right. Songs that made me want to sing. … Eventually, we had all these songs and we thought, why not do a cabaret.

Does it feel odd to be on stage just to sing, not to act?
I'm not just singing. I've never wanted to do just a singing thing. So from the start, I've worked to create a whole show, and one of the things I love most is telling stories and making people laugh. So I thought I'd write something that could go with the songs.

The press release says you'll be doing selections from the Great American Songbook?
I guess they had to say something. I don't know the Great American Songbook, personally.

What songs are we talking about?
One of my favorite songs I have always loved singing is "Since I Fell for You." I just love singing that song. And then there are songs about going on the road, like "Any Place I Hang My Hat Is Home," which is about the adventure of different people and different places. … And [Gale and Janas] introduced me to Michel Legrand's music. That was amazing. His song "You Must Believe in Spring" gives me goose bumps, so I love to sing that.

Why choose Philly for your grand debut as a grand dame of song?
I believe in going out of town [with a new show], and Philly is a perfect location between New York and Washington. And it's also because of the Philadelphia Theatre Company itself. I've worked with them and I've supported them. The new artistic director, Paige Price, is willing to be quite innovative about what is being done at the theater. … And my idea is to use [her approach] to create a template for other regional houses.

Smoky, sultry, husky. So many words have been used to describe your voice. What adjective would you use?
[Turner laughs, then shifts gears.] You know, one of the things I have discovered working with [Gale and Janas] on my singing is that I have a range. I used to do the Lauren Bacall joke, "I have a range from A to B." I mean I can sing "Ol' Man River" as it was originally done. My voice is all the … down there. But it turns out I have a range from A to like F or G, which is really exciting and it's something I never knew.

Kathleen Turner: "Finding My Voice"

Two sets, 7 and 9 p.m. Monday, Sept. 25, at Philadelphia Theatre Company's Suzanne Roberts Theatre, 480 S. Broad Street.
Tickets: $100 (limited back-row seats available for $75).
Information: 215-985-0420,