LOS ANGELES -- Forget Auto-Tune, iPods and digital downloading. The hottest thing in the recording industry is musical marriages.

The odd couple of Robert Plant and Alison Krauss, a rock god and the queen of bluegrass, dominated Sunday's Grammy Awards, winning album and record of the year. And collaborations -- some expected, some not -- made the 51st annual awards more memorable than many of the winning songs.

The Plant/Krauss album "Raising Sand" won five Grammys this year after getting one in 2008. Their mix of such American roots music as folk, blues, country and rockabilly was the right combination of inspiration and craft to win over the 11,000 voters in the Recording Academy.

Plant said he, Krauss and producer T-Bone Burnett initially figured they'd try working together for three days and then have a nice dinner. Instead, they completed an entire album that became a surprising blockbuster, selling 1.2 million copies.

Krauss, who has earned more Grammys than any other woman, now has 26 (conductor Georg Solti earned 31 while Quincy Jones has 27). Plant, who didn't win any while fronting Led Zeppelin, has eight.

"I'm bewildered," said Plant as he accepted for album of the year. "In the old days, we would have called this selling out. But it's a good way to spend a Sunday."

Backstage, the British star, who has made a career out of exploring American music, thanked Krauss for "patiently showing me the America I haven't been exposed to. America needs to know what its songs are all about."

If they gave trophies for live musical collaborations at the Grammys, there would have been many winners. The most ambitious mash-up was the best: the hip-hop hit "Swagga Like Us" with nine-months-pregnant M.I.A., T.I., Jay-Z, Kanye West and Lil Wayne (in a suit, like the rest of these male rappers).

Adele, winner of best new artist, proved herself worthy of the prize when she offered a heartfelt "Chasing Pavements," with Sugarland's Jennifer Nettles joining on harmonies.

Radiohead invited the USC Marching Band for a moody, mid-tempo "15 Step." Estelle charmed on "American Boy" with help from West, who participated in three performances. Justin Timberlake did double duty, joining T.I. for "Dead and Gone" and Al Green, for an 11th hour duet of "Let's Stay Together."

"I had 2 hours and 20 minutes' notice," Green said backstage.

He and Timberlake substituted for pop-soul siren Rihanna, who pulled out of the show at the last minute along with her pop-star boyfriend, Chris Brown, after a report of a domestic assault incident.

And don't overlook the thrilling, organic duet of Plant and Krauss on "Rich Woman" and "Gone Gone Gone."

A pair of solo performances stood out, as well: Carrie Underwood tearing it up on "Last Name" and Jennifer Hudson on the stirring "You Pulled Me Through" -- a fitting selection for the first-time Grammy winner whose mother, brother and nephew were murdered last fall.

Meet the Beatle

The emotional hero Sunday was Paul McCartney, whom the young stars fawned over.

When Coldplay took one of its three trophies, guitarist Jonny Buckland apologized to "Sir Paul McCartney for blatantly recycling Sgt. Pepper outfits."

Backstage, McCartney was his usual quick wit. "I didn't come to win it; I came to be in it," he said. But he was serious when asked about his performance of "I Saw Her Standing There" with Dave Grohl of Foo Fighters and Nirvana on drums.

"Sometimes in my career I'm lucky enough to find someone who's a great collaborator," McCartney said. "The obvious example is John [Lennon]. We lucked out. Since then, I've worked a lot of people. You have to trust them. My latest is Youth from Killing Joke," the British punk-rocker with whom he records as the group Fireman. "He's a friend. We work well together."

Among the multiple winners were Lil Wayne, Radiohead, Metallica, Adele, Kirk Franklin, Sugarland, Kanye West and Al Green.

Among the first-time winners were Southern rockers Kings of Leon, who beat out giants Coldplay, AC/DC, the Eagles and alt-rock heroes Radiohead for best rock performance by a group with vocals ("Sex on Fire").

But some still-active senior citizens also were acknowledged with Grammys: Pete Seeger, 89, B.B.King, 83, and Elliott Carter, 100.

Jon Bream • 612-673-1719