Lady Gaga to perform at staffers' ball

Watch out, Beyoncé and Katy Perry. There's another diva set to perform during the inauguration festivities -- Lady Gaga.

A person familiar with the inauguration tells The Associated Press that the pop star will perform at Tuesday's ball for White House staffers. The source spoke on condition of anonymity because they weren't authorized to reveal the information.

The staff ball is typically a private affair. During the last inauguration festivities, Jay-Z reportedly performed at it.

According to one attendee, Jay-Z rapped a riff on one of his hit songs, "99 Problems but George Bush Ain't One," to the delight of the young staffers who worked to elect Barack Obama in 2008.

Meanwhile, first lady Michelle Obama and daughters Sasha and Malia rocked out with hundreds of kids from military families and Washington-area public schools at the Kids' Inaugural Concert.

Pop star Usher started off the proceedings last night with his hit song "Yeah." The concert was chock-full of A-list talent, including Perry, Mindless Behavior and members of the cast of the Fox series "Glee."