Lady Antebellum are already in Los Angeles preparing to take the stage for their performance in Sunday night's Grammy Awards.

The group is nominated in six categories and will most likely take the stage to accept an award at some point in the night, but the country super-trio seems to be more nervous about entertaining the crowd with their performance than winning a trophy.

"We're rehearsing," vocalist Charles Kelley tells E! News. "They're throwing us a few curve balls."

The threesome won't give up any surprises of the show, but they do promise the audience    "We're going to do a medley of a couple of our singles, and then we have a little surprise we don't want to give away," Kelley hints.

Fellow lead singer Hillary Scott adds that the mystery might have nothing to do with their singing, claiming, "It's really stripped down ... You should see my outfit!"

Lady A's popularity has skyrocketed in the last few years as they have won 18 major awards and have scored four No. 1 hits. However, the grateful and humble band, who are currently rocking their first headlining tour, admit that their fame hasn't change them that much besides their appearance.

"My hair color changes every six months," Hillary says.

The Grammy Awards will air live from Los Angeles at 8:00 p.m. ET on CBS.