It has taken 12 years, motherhood, five albums and a glossy image revamp, but Liz Phair has finally convinced the music flock that she's an adult. A polished, expensive shoe-buying, PTA-attending adult, at that.

In October Phair, 38, will release Somebody's Miracle, an album as far removed as possible from her 1993 debut, Exile in Guyville, the raw record that had critics and fans alike crowning her the ultimate indie princess. Then, she was profane, vitriolic, and explicit about sex and life in general, making Exile the Rosetta stone for all aggressive rock chicks -- the Avril Lavignes and Fiona Apples of the world -- to come. Now, Phair sings about keeping the romantic embers glowing and regaining a little of the innocence of first love, all backed by poppy, instantly recognizable melodies.

The transformation didn't occur overnight. It evolved instead over the span of a decade and three albums, Whip-Smart, whitechocolatespaceegg and Liz Phair. And though Phair never hid the fact that all these changes were happening -- she married and divorced film editor Jim Staskauskas, father of her son, Nick, now eight; moved from her hometown of Chicago to Los Angeles; got blonder highlights and started wearing more expensive clothes -- the press and some fans refused to recognize that Phair had outgrown her indie persona. In fact, they vilified her, branding her a sellout when Phair's eponymous album came out two years ago, featuring a slick studio production and big-budget videos backed by Capitol Records. Of course, her new, cleaned-up, designer-studded look only compounded her traitorous turn to mainstream.

Phair's response to the critical maelstrom was simple: This is me. However, she has since garnered a different fan base, much of it unaware of her past, and early reviews of the lastest album have been positive. But for those few stray music critics and reluctant fans out there still waiting expectantly for Phair to return to the fold of the disgruntled underground -- well, they'd better get over it, because she has. "I left that scene at 27 or 28, long before everybody thought I had left it," she says. "I'm supposed to grow."

The fashion evolution was slow but distinctive. The leather biker boots of yore, for instance, were pushed to the back of her closet, making space for such items as a pair of green-and-white polkadot, ankle-tied Henri Cuir sandals Phair picked up at Barneys New York. Phair and her stylist, Nathalie Saphier, who has also worked with Maggie Gyllenhaal and Mandy Moore, have crafted a supersexy look that directly opposes the singer's earlier grunged-up style. For Somebody's Miracle, which features album art shot by fashion photographer Dusan Reljin, they've tapped into a glam bohemian vein that, with multiple beated necklaces, a few sequins and flowing blouses, fits Phair just fine, even when she's onstage tearing up the guitar.

"This is going to come out wrong, but I like to wear the least amount of clothes as possible because I need to feel free," says Phair, who barely clears five feet and nearly fills out a size two. "Unless it's in that kind of bondage-y, corset-y way. Like a bustier dress."

As with her music, Phair also prefers not to pigeonhole herself, and thus won't name any favorite designers, partly because she doesn't want to feel obligated to any particular label but also, she says, because it's not what she pays attention to. "I'm clueless about the larger [fashion] organization. Whatever floats up to me, I'm just encountering things, like 'Ooh, I like that,' or 'What's this?'" she says, miming plucking invisible dresses off floating racks.

Saphier, however keeps track of Phair's designer log, which includes a lot of Chloé, Jil Sander, Martin Margiela, Agent Provocateur, vintage Vivienne Westwood and the two labels the stylist designs for: her own signature line and Isabel Marant. Saphier notes that, since Phair is headstrong, she can really dig her heels in when it comes to trying on clothes she thinks won't look good. Case in point: a pair of high-waisted Balenciaga pants -- a tough look for anyone, especially someone as tiny as Phair. But once she put the pants on, says Saphier, "Liz was like, 'My legs look six feet long.'"

Phair also definitely indulges her girly side. When presented at the W fashion shoot with several Mary Buck-designed crowns, made of twisted strands of either gold or silver and accented with shiny carnelians, citrines and garnets, Phair actually squealed with delight and perched one, slightly aslant, on her head for a photograph. (Her guitarist and boyfriend of two years, Dino Meneghin, who's 10 years her junior, wants to buy her one as a present.)

As if all this weren't enough to irk the hard-core devotees of Phair's indie past, they'd be downright outraged to hear her in the midst of a bona-fide fashion rant. "What are bell-bottoms for?" she asks the style arbiters at large. "Why are they back? In California, they're still going." And while she's on the subject, she thinks that the bell-bottom's distant cousin, the bootcut, can get lost too.

Horror of horrors, Phair might even think about fashion enough to come up with her own style philosophy, as in her rather esoteric belief that no outfit can ever be worn the same way again. "You wear one thing one night and it's perfect for that exact day, that exact weather," she muses. It's almost the collective unconscious of fashion. It never works to re-create. It's so subtle, but you have to really keep your finger on so many different things, like what jewelry you were wearing or what time of the month it was for you. There are too many variables."

One variable she can control, though, is whether or not she stays away from cold weather. Phair, who grew up in a Chicago suburb, has had her fill of winter -- the reason why she hasn't settled in what she says is her favorite city, New York. "Winter's really hard for me because I'm so small that, in a lot of fabric, I get lost," she says, firing off the rest of her list of frosty woes. "You're so bundled and trundled. I'm less pretty in the winter. I kind of disappear. I pale out. I look like someone's old biege carpet."

Plus, the Cali babe look -- long blonde hair, a healthy tan and trim figure -- becomes her. Phair, who is nearing 40, looks considerably younger. Up close, her skin is beautiful. And she exudes the sexuality that is so often a subject of her songs.

Reljin recognized it immediately. "Liz has a very strong sex appeal which you notice the second she walks in the room," he says. "It's not fake, so it was easy to transform it into pictures."

Phair dismisses out of hand any notion that a woman edging toward middle age needs to hide herself behind either a staid dress or staid behavior or that expressing sexuality she should be left to the pop moppets who are barely past the drinking age. "It's a complete travesty; it's bull," the singer says. "My grandmother remarried twice after the age of 70, and I caught her having sex. She had a life and she was giddy and loud at the age of 78. I know it doesn't stop after a certain age."

So really, Phair hasn't changed all that much since she entered the foreground of music -- she is just as unapologetic about who she is and what she thinks as she ever was. All signs point to Phair's continuing to do just as she pleases for a long while, whether it's sitting on the sidelines of the pop-culture mainstream or swimming along with it.

"You know, I make the record that I want to make and then just wait for the storm," Phair says of the pending response to the album and, ultimately, herself. "I just put up the umbrella. And maybe now I know to put on the galoshes too."