Rapper 50 Cent aka Curtis Jackson and "Nashville" actress Hayden Panettiere
The Backstreet Boys hang out backstage.
Lady Antebellum drink up!
Nicki Minaj and Taylor Swift chat during a commerical break.
Rapper Swizz Beatz, singer Chris Brown and rapper Chris 'Ludacris' Bridges.
Carrie Underwood gets ready to perform.
... and she wows the crowd!
Justin Bieber celebrates his win with his mom.
Actress Stacy Keibler dances in the crowd.
Carly Rae Jepsen cheers in the audience.
Psy, MC Hammer and will.i.am pose backstage.
Psy gets the crowd pumped up.
Brandy and Usher chat backstage.
Pink stretches ahead of her dance-heavy performance.
Nicki Minaj, Cyndi Lauper and Taylor Swift.
"Once Upon a Time" actresses Ginnifer Goodwin and Jennifer Morrison pose backstage.