LOS ANGELES - Pop singer Amy Winehouse, whose rapid decline into an abyss of drug abuse shocked fans last year, won five Grammy Awards on Sunday after taking a break from rehab to perform at the show from London.

But jazz veteran Herbie Hancock was the surprise winner of the coveted album of the year award for the all-star Joni Mitchell tribute "River: The Joni Letters," preventing Winehouse from enjoying a historic clean sweep of the top four Grammy prizes.

Still, Winehouse, 24, won the most awards at the ceremony. Her tally for the night included record and song of the year for her signature hit tune "Rehab," and best new artist. Hip-hop star Kanye West, who had led the field with eight nominations going into the awards, ended up with four victories.

Winehouse's "Back to Black" and West's "Graduation," both commercial and critical successes, were considered the front-runners for album of the year. The loss was likely a huge blow for West. The outspoken artist made his displeasure loud and clear after he lost the race with his two previous albums.

Hancock's win was the first by a jazz instrumental release since Stan Getz and Joao Gilberto's "Getz/Gilberto" in 1965.

The pianist and composer also won the contemporary jazz album Grammy, bringing his career haul to 12. Virtually no one among the Grammy pundits had expected him to take the big prize. Even his nomination was a surprise.

"It's immeasurable how surprised I am," Hancock, 67, told reporters backstage. "I didn't even hear my name at first, and I was waiting to hear my name, and they said it, and I didn't hear it. And then I heard the word 'River' ... Is this happening?"

The 13,000 industry professionals who vote for the Grammys do occasionally surprise in this category. In 2001, an obscure album by veteran rock duo Steely Dan took the award over the heavily favoured rap star Eminem.

Even without the album of the year, Winehouse savoured a tentative comeback. Three weeks ago she was filmed appearing to be smoking crack cocaine at a party. A little later, she entered a London rehab clinic.

Because of her drug treatment - and problems getting a U.S. work visa - Winehouse performed "Rehab" and the equally personal "You Know I'm No Good" live via satellite from a London recording studio decorated as a cabaret.

Sporting her usual beehive bouffant and a ruffled black sleeveless mini-dress, she performed confidently, offering a few sly grins along the way.

During both tunes, she amended the lyrics to mention her husband, Blake Fielder-Civil, who is languishing in a London prison facing serious charges related to a pub brawl.

Winehouse also won Grammys for female pop vocal solo performance for "Rehab," and pop vocal album for "Back to Black." With five Grammys, she ties Lauryn Hill, Alicia Keys, Norah Jones and Beyonce for the most wins in a year by a female artist.

West's awards were all in the rap category: rap album for "Graduation," rap solo performance ("Stronger"), rap performance by a duo or group with vocals ("Southside"), and rap song ("Good Life"). His career haul is 10 statuettes.

Still mourning the death of his mother, college professor Donda West who died in November after plastic surgery, West performed an emotional version of his song "Hey Mama." He had also shaved the word "MAMA" into the back of his head.

In accepting the best rap album Grammy for "Graduation," he declared a little too confidently that he had made the Grammys his "new place of residence."

Country singer Vince Gill provided the best laugh of the evening a little later, when Ringo Starr presented him with the country album of the year award for "These Days."

"I just got an award given to me by a Beatle," he said. "Have you had that happen yet, Kanye?"