NEW YORK — On stage, the more Amy Winehouse drinks, the better she sings, which is often the case. She's the hottest voice you've never heard — her album hit No. 1 back home in England — but right now, at her first U.S. concert, her nerves are bedeviling her. She makes awkward chitchat in that cockney twang. Tugs distractedly at her trademark ratty 'do. Yanks nervously on the strapless shift that's sliding dangerously south.

Finally, she requests an amaretto sour — to hoots of approval. It's a part of her shtick, what her fans have come to expect.

"They keep trying to keep me from drinking, but they forget it's my gig." Pause. Sip. "Ahhhhhhhhhhh." She cocks back her head, then lets loose, her voice big, brassy, bitter, giving the lyrics to her single, "Rehab," a certain squirmy poignancy: "They tried to make me go to rehab, but I said no, no, no ... "

To witness Winehouse is to wonder why art and self-destruction so often dance together. A self-described "violent drunk," Winehouse, 23, is showing signs of careering off the rails, even as she's planning her stateside debut this March with her sophomore album, "Back to Black." (Her critically acclaimed first album, "Frank," was never released in the U.S.)

On a good day, she's blowing them away at Joe's Pub in Manhattan or packing the house at an industry showcase in Cannes. On a bad day, well, check out that YouTube video of her slurring through "Beat It" in a televised duet with Charlotte Church. The British tabloids feast on Winehouse's troubles: her shocking weight loss, the time she slugged a fan at a club and then slugged her boyfriend, too.

For now, at least, all seems well at Joe's Pub at the Public Theater, a downtown venue where Winehouse's label, Universal Republic Records, has set up a showcase. Outside, hipsters are lining up, hoping to snare a scalper's ticket to the sold-out show. In the audience are Nona Hendryx, Citizen Cope and Dr. John. Backstage, Mos Def will scrawl his number on her jeans, invite her to hang out. Her producer, Mark Ronson, who's worked with Lily Allen, Christina Aguilera and Radiohead, will stop by. Jay-Z will tell her how much he loved her record.

Her word for it: "surreal."

Coming up is an appearance on "Late Show With David Letterman" to plug her CD (out March 13), MTV tapings and spreads in Rolling Stone, Paper and Vibe. All part of a push to sell a green-eyed, white British soul singer to the country that invented soul.

To which Winehouse says: "I don't give a (expletive). ... If I had my choice, I'd be a roller-skating waitress in the middle of nowhere, singing songs to my husband while I'm cooking grits somewhere. What I'm doing I'm so grateful to be doing — it's so exciting, so fun. But I've never been the kind of girl who knocks on someone's door and says, 'Make me famous.' "

BENEATH THE MAKEUP

With her towering ebony beehive ("Yeah, it's all mine, 'cause I bought it"), Elvira batwing eyeliner and plush red lips, Winehouse evokes a 21st-century Ronnie Spector — if, that is, girl-group queen Ronnie were given to decorating herself with tattoos of naked pinup girls. Aurally, she evokes comparisons to Sarah Vaughan and Dinah Washington, to Dusty Springfield and Nina Simone. Hers is a voice marinated in regret and pulsing with pain, yet soaked in snarkiness while fully rooted in the saccharin sensibilities of '60s girl groups.

It wasn't always like this, all this raw emotion and need. A few years ago, she was curvier and rosier in outlook. Her jazz-soul album "Frank" had a decided rap influence, and was filled with scathingly sardonic observations. The British press dubbed her a "modern Billie Holiday," and in 2004 she won two important nominations: best British female and best urban act at the Brit Awards (the equivalent of the Grammys). But then two things happened between "Frank" and "Back to Black."

"I started drinking, and I fell in love," she says, flinching as a makeup artist gingerly dabs pancake over her pale skin at a photo shoot the day after her Joe's Pub concert.

Heartbreak ensued. To listen to the lyrics from "Back to Black" is to eavesdrop on the past three years, the rejections, the selfhatred, the his-and-hers betrayals along with sly references to Ray Charles and Donny Hathaway and Sammy Davis Jr. Pain seasoned her voice, deepening it until it took on the husky timbre of a much older and sadder woman.

Despite her bitter blue-collar persona, Winehouse grew up middle class in northern London. Her mother, a pharmacist, and her father, a cabbie, split when she was 10. As a kid, jazz was all around her, from her mother's musician brothers to her grandmother's Sinatra CDs. Winehouse recalls that Ella Fitzgerald and Dinah Washington, Sarah Vaughan and Carole King sang backup to her formative years.

School never quite stuck; she entered and quickly exited posh private schools.

A demo she made ended up with Universal Island Records and at 19 she released "Frank," to instant praise and a whole lot of attention she wasn't exactly prepared for. She inserted stiletto into mouth with regular frequency, insulting her record label and her management company, Brilliant/19, headed by Simon Fuller, the force behind the Spice Girls and "American Idol." (Of her label she once said: "The marketing was (expletive), the promotion was terrible, everything was a shambles.")

"I try to think about things before I say them nowadays," she admits. "I'm a lot less defensive with this record. ... I'm just so proud of it. I think the record speaks louder than any of my stupid actions or things that I say."

Winehouse says of various published reports about her alleged bulimia, anorexia and bipolar disorder, "It got blown out of proportion." She does say that she suffers from depression, and that she's not the most secure person in the world. But then, she says, neither is any other musician she knows.

STANDING OUT

Other British chanteuses have tapped the U.S. market, among them Corinne Bailey Rae and Joss Stone. So how do you sell another old-school soul record these days?

It helps to have a controversial "story." It also helps to be known as a train wreck with talent.

"She's got a great voice; she's got great songs, she's already coming with a larger-than-life persona," says Bill Bragin, director of Joe's Pub.

By the time Winehouse landed in the U.S., interest was stoked. Tickets to the sold-out concerts were being hawked on Craigslist for upward of $200.

Her label is launching a marketing offensive calculated to break Winehouse across musical genres. The rapper Ghostface Killah did a remix of "You Know I'm No Good." The label is in talks with Starbucks to do in-store marketing.

For Winehouse, the day after her Joe's Pub appearance requires a different sort of performance — an exhausting photo shoot in a Manhattan loft. A half-dozen sessions are crammed into a seven-hour slot, with stylists and photographers from different publications standing at the ready.

Winehouse arrives an hour late with her tour manager, looking frail, apologizing again and again for her lateness. None of her trademark bravado is on display. She's shy, and she's shaking. She stutters and searches for words, eyes welling with tears. Her left arm is abraded and raw, she isn't sure why. "I got drunk and I don't remember."

The day wears on, with Winehouse trying on and rejecting one outfit after another. Crew members roll their eyes and mutter. Nerves are fraying. As the clock pushes past 7, Winehouse, fortified with champagne, warms up, laughing and giggling. But five minutes later, as a photographer snaps her picture, she starts smacking herself in the face — hard — and then abruptly bolts, in tears. (Later, she will say that she just didn't feel pretty enough and was worried about disappointing everyone.)

She huddles with her managers. A bit later, she returns and finishes the photo shoot, posing like a pro, perching on a prop bathtub, all studied attitude.

When she finishes, she hugs the photographer.