2012 American Music Awards opens with Usher, closes with PSY and MC Hammer

MC Hammer,left, and singer PSY perform onstage during the 40th American Music Awards on Nov. 18, 2012 in Los Angeles.
Kevin Winter/Getty

The 40th annual American Music Awards ceremony Sunday night began and ended with high-energy performances.

Korean rapper PSY and MC Hammer brought down the curtain with a collaboration that had Hammer joining PSY on his viral hit "Gangnam Style," complete the trademark horse-riding dance, and PSY rocking out with Hammer on "Too Legit to Quit.''

Usher kicked off the three-hour show with green laser lights beaming onstage as he performed a medley of songs, including "Numb," "Climax" and "Can't Stop, Won't Stop," which featured a smoky floor and a number of backup dancers. Usher jammed in all black, with the exception of his red shoes.

In between these acts were several strong performances. Justin Bieber gave a stripped down, acoustic performance of "As Long As You Love Me," then transitioned to the dance-heavy "Beauty and a Beat," where Nicki Minaj joined him onstage, grinding with the teen for a few seconds.

Minaj, who wore three different wigs and four outfits throughout the night, was in an all-white get-up, including fur coat and pink hair when she performed her new song "Freedom." The scene was ghostly and snowy, as a choir also in white joined her onstage.

Country star Taylor Swift gave a masquerade-themed performance of the pop song "I Knew You Were Trouble." She sang onstage in a light dress while dancers wore mostly black. But then she changed into a red corset and black skirt, matching their dark mood. She even danced and sang on the floor as lights flickered throughout the performance.

Ke$ha's "Die Young" performance was tribal, with shirtless dancers in skin-tight pants, silver hair and skeleton-painted faces. They also played the drums.

Kelly Clarkson also hit the stage, making a nod to her "American Idol" roots with a number on her dress and three judges looking on as she sang "Miss Independent."