EXCLUSIVE: Mary J. Blige to perform at the ET/People Emmy party!

If you haven't gotten your invite to the Sept 20 Entertainment Tonight Emmy party --  sponsored by People magazine -- and held at Vibiana in downtown L.A., start making those pleading phone calls now.

But good luck getting a ticket now that we just got the exclusive word that Mary J. Blige will perform that night!

Blige joins a hot list of past performers that includes Billy Idol, Prince and Duran Duran.

Photo: WireImage