The 24th annual event at the Palms in Las Vegas. Performers include Britney Spears, Akon, Chris Brown, Cee-Lo, Common, Fall Out Boy, Foo Fighters, Nelly Furtado, Gym Class Heroes, Alicia Keys, Adam Levine, Lil Wayne, Mastodon, Daniel Merriweather, Rihanna, Soulja Boy, Serj Tankian, T.I., Timbaland, T-Pain, Kanye West and 50 Cent.