Amy Winehouse, the Grammy Award-winning pop singer-songwriter whose sultry and profane compositions reflected — and ultimately were overshadowed by — a turbulent personal life and struggles with alcoholism and drug addiction, was found dead July 23 at her apartment in London. She was 27.

Police sources confirmed her death, but said no post-mortem results would be released before Monday.

The British-born performer’s train-wreck-style public behavior often threatened to eclipse her talent. Although she received high-profile engagements, such as Nelson Mandela’s 90th-birthday concert at London’s Hyde Park in 2008, she routinely canceled or missed appearances, whether because of bad health or bad manners.

In June, Ms. Winehouse canceled a tour after she shouted “Hello, Athens!” to an audience of 20,000 in the Serbian capital of Belgrade. She appeared to be so inebriated that backup singers had to sing her songs when she proved incapable, and she was ultimately booed off the stage.

Ms. Winehouse said living dangerously generated her creativity, and she was often photographed half-dressed, wild-eyed and disheveled. The English tabloids reported she had suffered brain damage from excessive use of drugs and alcohol.

“It sounds like such a wank thing to say,” Ms. Winehouse once commented, “but I need to get some headaches going to write about.”

Her reckless life often called to mind the doomed pop stars of earlier generations, including Janis Joplin, Jimi Hendrix, Jim Morrison and Kurt Cobain — all of whom also died at the age of 27.

She had a fondness for jazz-inflected vocals and 1960s pop, but she roughed up the style to include hip-hop slang and an infusion of profanity. Her music often focused on drinking, drug-taking and chronic infidelity.

Her song “Rehab” mirrored her life through its defiant lyrics: “They tried to make me go to rehab / I said no, no, no.” The bouncy song, styled after the early Motown sound and 1960s girl groups, became a ubiquitous hit in 2007.

Amid the chaos and turmoil of her personal life, Ms. Winehouse won five Grammy Awards in 2008, including best new artist. She also won for song of the year and best female pop vocal performance for “Rehab,” as well as for record of the year and best pop vocal album for “Back to Black.”

Music critic Chuck Arnold wrote of “Back to Black” in People magazine that Ms. Winehouse “turns a righteous girl-group groove into a rebellious bad-girl anthem, as if Courtney Love has crashed Martha and the Vandellas.”

She was supported by a first-rate production team in her recordings, but she did not always appear first-rate in live performance. New York Times music reviewer Jon Pareles wrote of her May 2007 appearance at Manhattan’s Highline Ballroom, “Her voice glints with possibility: tart, smoky, ready to flirt or sob, and capable of the jazzy timing of a Dinah Washington or the declamation of soul singers like Martha Reeves and Carla Thomas.

“What she doesn’t have, and may not want, is the kind of focus the older singers brought to their songs,” he wrote, adding that her performance “switched between confession and indifference.”

Ms. Winehouse was barely out of her teens when she reached the top of the music charts in England with her debut disc, “Frank” (2003). The album was released in the United States in 2006.

Although the title alluded to singer Frank Sinatra, it could also have been a reference to Ms. Winehouse’s libido-charged lyrics, such as the provocatively titled “[Expletive]-Me Pumps.” In interviews, her candid remarks often suggested a promiscuous sex life.

Not all of her songs were racy or lustful, however. “October Song” eulogized her dead canary, which she buried in a Chanel sunglasses box. In addition to her original songs, her debut album included two jazz standards, “There Is No Greater Love,” in which she channeled another drug-haunted singer, Billie Holiday, and “Moody’s Mood for Love.” Another of her original songs, “Stronger Than Me,” won the Ivor Novello Award for best contemporary song from the British Academy of Composers and Songwriters.

Just as her songs often suggested earlier eras of pop music, Ms. Winehouse’s stage appearance was something of a throwback. She revived fashion trends with her large beehive hairdo, heavy eyeliner, deep-red lipstick, vintage skirts and high-heel pumps. Designer Karl Lagerfeld spoke flatteringly of her, saying she reminded him of Brigitte Bardot, a French sex symbol of the 1950s and ’60s.

Amy Jade Winehouse was born Sept. 14, 1983, near London in Enfield, Middlesex, to a taxi-driving father and a pharmacist mother.

Her parents divorced when she was 9, but their musical tastes — especially for such pop singers as Sinatra, Dean Martin and Julie London — influenced their daughter’s enthusiasm for jazz and pop music, even as she was performing with a school chum in a rap group called Sweet ’n’ Sour. She was Sour.

Her paternal grandmother encouraged her to attend theater classes, and she won a scholarship to the prestigious Sylvia Young Theatre School in Croydon, near London. She was expelled for piercing her nose, and she was defiant about the experience in later years.

“The thing about stage school,” she said, “is that it doesn’t prepare you or train you for your skills.”

Singer Tyler James, her then-boyfriend, shopped a demo of her original songs to various record companies. Universal-Island Records in England signed Ms. Winehouse to a recording and publishing deal.

It took Ms. Winehouse three years to complete a follow-up CD to “Frank.” During that time, her manager, Nick Godwyn, terminated her contract when she refused to seek treatment for alcoholism. Ms. Winehouse later admitted to suffering from depression.

With “Back to Black,” the jazz inflections of the earlier album gave way to a 1960s pop music aesthetic reflected in the songs “Rehab” and “You Know I’m No Good.” She also did the backup vocals for co-producer Mark Ronson on his hit “Valerie,” yet another song in a retro vein.

In May 2007, Ms. Winehouse flew to Miami and secretly married her boyfriend, Blake Fielder-Civil, an admitted heroin and crack-cocaine user. As her records soared up the charts that year, her professional success gave way to a series of personal drug- and alcohol-related mishaps, many involving her husband, that the British press covered relentlessly.

The incidents included a canceled U.S. tour, a five-day stay in rehab with Fielder-Civil, a marijuana bust while touring in Norway, and her husband’s incarceration in November 2007 for attacking a pub owner and attempted bribery.

Most explosively, the London Sun newspaper posted a grainy video on its Web site in January 2008 — about a month before she received her Grammy Awards — allegedly showing Ms. Winehouse smoking a crack pipe and talking about taking ecstasy and Valium.

Her father, Mitch Winehouse, told reporters that his daughter — once plump but later skeletally thin — had an eating disorder. He said his daughter and Fielder-Civil were heroin addicts who cut themselves as a distraction from the pain of drug withdrawal.

Throughout 2008, the singer’s appearances were infrequent and fueled speculation about her health. She canceled more appearances and was booed at two British festivals when she arrived late.

Mitch Winehouse announced to the media that his daughter had emphysema and might soon need to use an oxygen mask if she didn’t stop smoking crack cocaine and cigarettes. A spokesman for the singer later confirmed the diagnosis and said she was being treated with nicotine patches.