Robert Plant, left, and Alison Krauss show off their trophies for album of the year and best pop collaboration with vocals backstage Sunday at the 51st Annual Grammy Awards in Los Angeles. Krauss has won 26 Grammys in her career.

LOS ANGELES — The 51st annual Grammys was an all-ages affair ultimately dominated by a rock legend who took up with a younger bluegrass singer on a whim.

The unlikely pairing of Robert Plant and Alison Krauss that produced the hit album "Raising Sand" won five Grammys on Sunday including album of the year. The former Led Zeppelin frontman, previously best known for his high-decibel shrieking and rock star theatrics, found more docile Nashville melodies with Krauss.

While accepting the Grammy for album of the year, the 37-year-old Krauss — perhaps wanting to remind the audience that Plant's rock star hadn't entirely matured — said there's "never a dull moment" with the 60-year-old singer.

"Raising Sand," produced by T. Bone Burnett, bested fellow nominees Lil Wayne, Ne-Yo, Coldplay and Radiohead. Their "Please Read the Letter" also won record of the year.

"I'm bewildered," said Plant. "In the old days we would have called this selling out, but I think it's a good way to spend a Sunday."

In a performance-stuffed live broadcast on CBS, the subject of age — and intertwining musical realms — was always close at hand.

Taylor Swift, 19, and Miley Cyrus, 16, sang a duet of Swift's "Fifteen." The 66-year-old Paul McCartney, with 40-year-old Dave Grohl on drums, sang the Beatles classic about a girl who "was just 17."

Stevie Wonder performed with the Jonas Brothers and even the nine-months pregnant rapper M.I.A. hobbled out on the stage to join the dapperly dressed Jay-Z, Kanye West, Lil Wayne and T.I. in a "rap summit" performance of T.I.'s "Swagger Like Us."

Before the night's end, Plant and Krauss seemed to be in a three-horse race with Lil Wayne and Coldplay — a trio of acts of wildly different sounds.

Lil Wayne — who led the field with eight nominations — won three awards, including best rap album for "Tha Carter III," for which he literally hopped on stage to receive. (His tally came to four Grammys if you count his inclusion on "Swagger Like Us," which won best rap performance by a duo or group.)

Coldplay also took home three awards, including best rock album for "Viva La Vida Or Death And All His Friends."

The Grammys this year offered a CBS telecast without a host and — unexpectedly — without several performers.

Rihanna and Chris Brown, both nominated for awards and scheduled to perform, were absent after the Los Angeles Police Department announced that Brown — who is dating Rihanna — was the subject of an investigation into a felony domestic violence battery.

To fill in for Rihanna's scheduled performance, the Recording Academy hastily put together an ensemble of Al Green, Justin Timberlake, Boyz II Men and Keith Urban performing "Let's Stay Together."

List of awards presented during Sunday's telecast of the 51st annual Grammys:• Album of the Year: "Raising Sand," Robert Plant and Alison Krauss• Rap Album: "Tha Carter III," Lil Wayne• Male Pop Vocal Performance: "Say," John Mayer• Record of the Year: "Please Read the Letter," Robert Plant and Alison Krauss• New Artist: Adele• Rock Album: "Viva La Vida or Death and All His Friends," Coldplay• Pop Collaboration With Vocals: "Rich Woman," Robert Plant and Alison Krauss• Song of the Year: "Viva La Vida," Guy Berryman, Jonny Buckland, Will Champion and Chris Martin, songwriters (Coldplay)• Country Performance By a Duo or Group With Vocals: "Stay," Sugarland• R&B Album: "Jennifer Hudson," Jennifer Hudson