Jay-Z, Usher, Mariah Carey Backstage at So So Def 20th Anniversary Concert

Jermaine Dupri's So So Def celebrated 20 years with a star-studded anniversary concert held in Atlanta over the weekend. In addition to So So Def acts like Jagged Edge, Bow Wow and Kris Kross, the concert brought out Dupri's pals Jay-Z, Mariah Carey, Nelly, Usher and more to perform. Check out highlights from backstage and onstage.