Liz Phair is one of rock's most enduring sex symbols. At 36, the blond singer-guitarist is hotter than ever, with a gym-shaped tight bod and a newly revised career.

The sexually explicit Phair, who became a rock cause célèbre with her 1993 debut album, Exile in Guyville, has connected to a whole new audience via her defiant song of sexual liberation, "Why Can't I?" It's on the new Now That's What I Call Music! Vol. 14 CD, along with the likes of Beyoncé, Justin Timberlake and Good Charlotte. It was on the soundtracks of How to Deal and Win a Date with Tad Hamilton!, and is a hit on radio and MTV.

"Ohmigawd, when I hear myself at my own gym, it cracks me up so much," she said in a phone interview from her home in Manhattan Beach, near Los Angeles. "I just smile to myself and walk around. Nobody has any clue as to who I am. It's great. It's really fun."

Suddenly, she was interrupted by someone.

"Can you hang on one second?" she asked. "I'm hosting a play date."

Hmmm. A play date with Liz Phair! Hot stuff!

"You can't watch that," she could be heard saying to someone. "You see where it says 'T', for Teen? That's too old for you guys. You gotta go for the 'E's. 'E' is for everybody."

Turns out the playas she was hosting were her son, Nicholas, 6, and some of his friends, who were picking out a video game.

Phair has no qualms about being a divorced mom who sings frank songs about sex.

"You can be a responsible grown-up and do everything right," she explained, "but there's still these wild impulses in you that have to be allowed, because otherwise you lose your humanity — like a LizBot 2000. Somehow I know it's not good for your kids to be always in control, like that's just not right."

That's similar to the view expressed in "Extraordinary", the rocking song that opens her new, fourth album, which is called simply Liz Phair.

"I am just your ordinary, average, everyday, sane/psycho supergoddess," she sings exultingly.

"There's gotta be some kind of reflection of nature," she said, referring to the characterization of herself as "sane/psycho". "And that's the psycho part. Nature is both sane and psychotic."

"I'm not writing from the point of view of a newly experienced person. I'm writing from the other side. I've been married, I have a kid. I believe it truly would be a wonderful day if young women could explore and learn about their own sexuality without having all the crap around that men are the enemy."

The most controversial cut on her new CD is titled "H.W.C.", a paean to semen.

"I knew what I was doing when I decided to put it on the record," she said, "'cause I knew that would be kind of a controversial thing to do. It was written very spontaneously and very naturally. I like to push buttons with people culturally, but it's not my main aim. Mainly, I'm just expressing the little things that I've been going through. That's the song that everyone yells for at the shows now."

She emphasized that it's tongue-in-cheek.

"It's hilarious on a number of levels," she said. "I've always, always had humor in my songs, going way back to the first Girlysound tapes I made at Oberlin College (later released as an EP). I'm not ha-ha funny. I'm more like wink-wink. I always mix the super-heavy with the ridiculous. It's just my style."

Opening her show Wednesday at the Moore are two promising young singer-songwriters, Patrick Park and Rachael Yamagata.