Jermaine Dupri had a star studded bash for the 20th anniversary of his So So Def Records, but he had an even more stellar set of guests than he realized. When people like Jay-Z and Mariah Carey are crashing your party, you know you've got a pretty sick set of pals.

Jigga opened his set for the celebration with 'Public Service Announcement' from 'The Black Album,' which he had to start over because he doesn't "f--- with the vocals." And let's be real, when the God MC demands, you follow. After 'PSA,' Dupri demanded some "new s---," and Hov launched into 'N----s in Paris.' Unfortunately, Kanye West was elsewhere talking smack about 'Suit & Tie' and couldn't perform his verses. Following his track from 'Watch the Throne,' Dupri requested that Hov perform 'Jigga What, Jigga Who (Originator 99),' but Hov opted for 'Clique' instead.

Later, the pair teamed up for the classic collabo, 'Money Ain't a Thing.'

Usher followed, performing a medley of his greatest hits, including 'My Way' and 'U Got It Bad.' He wasn't alone, though -- Ludacris joined him for an extended set, too.

The most divalicious 'American Idol' judge later surprised Dupri, wheeling out a cake and geeking out over her longtime pal, frequent collaborator and So So Def rapper Da Brat.

Watch Jay-Z + Jermaine Dupri Perform 'Money Ain't a Thing' at the So So Def Anniversary Party

Watch Usher + Ludacris Perform at Jermaine Dupri's So So Def Anniversary Party

Watch Mariah Carey + Da Brat Crash Jermaine Dupri's So So Def Anniversary Party