The summer's hottest reality competition show, "America's Got Talent," returns for its 10th anniversary season starring judges Howard Stern, Heidi Klum, Mel B and Howie Mandel, and hosted by Nick Cannon. In the 10th season premiere, variety acts of all types and contestants of all ages audition for the chance to win the $1 million prize. This season, the Golden Buzzer allows four lucky acts the chance to go directly to the live performance rounds at Radio City Music Hall to compete for America's vote.