* Mumford & Sons, Frank Ocean, FUN. vying for album of year
* Miranda Lambert, Carrie Underwood among country nominees
* Justin Timberlake, Elton John to perform
By Piya Sinha-Roy
LOS ANGELES, Feb 10 (Reuters) - Country music artists will share the spotlight with rising stars and veteran performers at the Grammy Awards on Sunday as they take the stage for music's biggest night.
Grammy organizers want to bring the attention back to the music this year, after the death of singer Whitney Houston the night before last year's awards ceremony cast a pall over the live show.
This year's key categories are dominated by male artists, with British folk band Mumford & Sons, indie-pop trio FUN. and R&B singer Frank Ocean going into the show with six nominations each, including for the top award of album of the year.
They will be among dozens of performers including U.S. rockers The Black Keys, who have five nods, and former White Stripes frontman Jack White, who has three nominations.
After paying tribute to electronic dance music last year, the Grammys are highlighting country music. Nominations were announced last December in a live concert from Nashville.
On Sunday, country will be represented by nominees Dierks Bentley and Miranda Lambert, Carrie Underwood and best new artist contender Hunter Hayes. Country music veterans Tim McGraw and Faith Hill will hand out awards.
The three-hour Grammy show, broadcast live on television, has a reputation for pairing up old-timers and newcomers.
On Sunday, Mumford & Sons will perform alongside Zac Brown, Elton John, Mavis Staples and Alabama Shakes singer Brittany Howard in a tribute to blues-rock musician Levon Helm of The Band, who died last April of throat cancer
Mumford & Sons won mainstream attention in the United States after performing at the 2011 Grammy show alongside the Avett Brothers and Bob Dylan. Their sophomore album "Babel" became one of 2012's top-selling albums in the United States.
JUSTIN TIMBERLAKE COMEBACK
But the Grammys are not just about those competing for awards. Justin Timberlake will make his long-awaited return to the musical spotlight in his first televised performance since he released "Suit & Tie" in January, his first new song in five years.
Timberlake, whose album "The 20/20 Experience" will be released on March 19, will also be performing a show in Hollywood immediately after his turn on the Grammy stage.
R&B artist Bruno Mars and Rihanna will team up with Sting, while John and British rising star Ed Sheeran, 21, are set to perform a duet.
Country-pop darling Taylor Swift did not release an album in time for the Grammy voting eligibility period, but she still scored a record of the year nod for her hit single "We Are Never Ever Getting Back Together" and will perform on Sunday.
Kelly Clarkson, Alicia Keys and best new artist nominees The Lumineers, an indie-folk band from Colorado, are also scheduled to perform.
The Grammy red carpet has seen some outrageous moments in previous years as stars pushed the fashion boundaries. But perennial scene-stealers such as Lady Gaga, Nicki Minaj and Justin Bieber all failed to score nominations this year and are not expected at Sunday's show.
Performers have been warned by the CBS network, which airs the Grammy Awards, to keep their buttocks, nipples and genitals covered up, in a "wardrobe advisory" aimed at avoiding indecency complaints from viewers and federal authorities.
Red-carpet moments this year are likely to come from Beyonce, who wowed millions on TV at her Super Bowl half-time show last Sunday and will be a presenter as well as a nominee in the traditional R&B performance category.
Beyonce is likely to be joined by husband, rapper Jay-Z, who is nominated for six Grammys. Kanye West, who is also competing in six categories, may turn up with his pregnant reality star girlfriend, Kim Kardashian.
Adele, who swept the Grammys last year with six awards, is back this year with one nomination for pop solo performance for her single "Set Fire To The Rain."
All eyes will also be on Rihanna and Chris Brown, who are both nominated, and who recently resumed their romance four years after Brown pleaded guilty to assaulting her on the eve of the 2009 Grammy Awards show.
The 55th annual Grammy Awards show will be broadcast from the Staples Center in Los Angeles.