Los Angeles  - The unlikely duo of former hard rocker Robert Plant and bluegrass queen Alison Krauss won five Grammys Sunday night, including the coveted album of the year for their collaboration Raising Sand. The duo also won Record of the Year for their haunting hit Please Read This Letter.

Coldplay won four awards, including Song of the Year for Viva La Vida. New Orleans rapper Lil Wayne also picked up three awards.

But the biggest night in music was overshadowed by a scandal involving two of the hottest young stars in the business. Rapper Chris Brown and his girlfriend, dance queen Rihanna, both pulled out of the show at the last minute as reports surfaced that Brown was wanted for questioning about an assault on an unidentified woman.

Later police identified Rihanna as the victim. According to celebrity website TMZ. com, Rihanna told police she and Brown got into an argument which turned violent. Police said that when they arrived at the scene, Brown had left, but the woman had "visible injuries and identified Brown as her attacker."

The couple's place in the performance roster was taken by Justin Timberlake, Al Green, Boyz II Men and Keith Urban who all sang Green's classic hit, Let's Stay Together.

Another notable performer was Jennifer Hudson, whose mother, brother and nephew were killed last year by her sister's estranged husband, and who sang an emotional song called You Pulled Me Through. Hudson took home the prize for best R&B album, her self-titled debut.

British singer Adele won the title of best new artist, ahead of the hot favorites the Jonas Brothers, Lady Antebellum, Jazmine Sullivan and Duffy. She also won best female pop vocal for her hit Chasing Pavements. John Mayer won the best male vocal performance for Say.

Apart from Song of the Year, Coldplay also picked up prizes for best rock album, best rock song and best pop performance by a group. Lil Wayne's awards included rap album for Tha Carter III and best rap song.

Plant and Kraus also won pop collaboration with vocals, country collaboration with vocals and contemporary folk album. "In the old days we would have called this selling out but I think it's a good way to spend a Sunday," said former Led Zeppelin guitarist Plant.

The show was filled with spectacular performances, notably a rare TV appearance for Radiohead, who performed together with a marching band. Paul McCartney performed I Saw Her Standing There with the Foo Fighters' Dave Grohl on drums.

But the most amazing performance of all came from MIA who performed her global hit Paper Planes on the very night she was due to give birth to her first child. (dpa)