� MTV Base So So Def marked its twentieth anniversary as a major record label in the music industry. To celebrate, So So Def label head, Jermaine Dupri threw a party in Las Vegas this past Saturday. Some of the stars who attended the party were So So Def artists Da Brat, Jagged Edge, Xscape, and Bow Wow, along with other hip-hop luminaries like Jay-Z, Usher and Mariah Carey.