Usher, Mary J. Blige and Duran Duran helped Andre Agassi raise more than $10 million for his charitable foundation Saturday night, when they played at the Grand Slam for Children at Las Vegas' MGM Grand Garden Arena. Celine Dion, Earth, Wind & Fire, Robin Williams and George Lopez were among the announced performers, while Barbra Streisand was a surprise guest. The Andre Agassi Charitable Foundation assists at-risk youth in Las Vegas via schools, scholarship funds, summer camps and youth organizations. - Courtesy MTV.com