Rockers Maroon 5 and country singer Taylor Swift were early winners at the American Music Awards Sunday, after an opening performance by Nicki Minaj wearing a costume that made her a human audio system.

Maroon 5 won for best pop or rock group behind its current hit Moves Like Jagger. Onstage, frontman Adam Levine thanked fans for voting the band its first American Music Award.

To get one of these, you have to have loyal fans, he said.

Taylor Swift won best country female artist for the fourth straight year. She thanked her bandmates, family and fans.

Hip-hop artist Minaj, backed by music spun by French DJ David Guetta, performed songs dressed in a metallic outfit that had two large speakers on her bottom. At one point, she plugged herself into a faux electric outlet on the front of her costume, delighting the crowd.

Teen sensation Justin Bieber also was among the early performers, singing his holiday song Under the Mistletoe.

Up later in the evening are the major awards, which figure to honor British singer Adele and pop stars Lady Gaga and Katy Perry, among the top nominees.

With her throat on the mend after recent surgery, Rolling in the Deep singer Adele entered the AMAs with a leading four nominations for her work on the smash hit album 21.

The awards telecast is among the most widely watched of the annual U.S. musical honors, next to the Grammys, and a long list of top artists will be on hand to claim trophies and perform, including Perry and rapper Pitbull.

Awards are divided into genres of pop or rock, rap or hip-hop, country and R&B. Nominees compete in categories for favorite artists and best albums.

ADELE LEADING NOMINEE

Adele's four nominations include best female artist in the pop or rock category, top album with 21, adult contemporary singer and the night's top honor, artist of the year.

The singer had a setback this month when she had surgery in Boston to treat a benign polyp on her vocal cords, which was causing recurrent bleeding. The surgery was a success but she is currently unable to perform.

Even though Adele is leading the AMA nominations, she faces stiff competition from Perry and Lady Gaga for best female artist and artist of the year. Also competing for artist of the year are rapper Lil Wayne and country sensation Swift.

Adele has enjoyed a huge year of sales with 21, which includes hit songs such as Rumor Has It, but her luck at awards shows has been mixed. At the MTV Video Music Awards, for instance, Adele's videos won some minor categories such as art direction but lost in top categories.

Perry won video of the year and Lady Gaga had best female video. Similarly, Lady Gaga came up a big winner at MTV's recent Europe Music Awards.

Elsewhere, several celebrities got three American Music Award nominations each, including Perry, Lady Gaga, Swift, R&B artist Rihanna and country sensations The Band Perry, which also earned a nod for best new artist in the country genre.