Katy Perry, Usher and the cast of 'Glee' were on hand to celebrate the inauguration of President Barack Obama for his second term. The festivities began the Kids Inaugural Concert, emceed by Nick Cannon and graced by the First Family and Vice President Joe Biden and Co. as well.

Billboard reports that Usher opened the party with his hit 'Yeah.' Rocking black leather pants, a matching tank and red kicks, Usher was sleekly patriotic in his own cool, smooth way. He also performed 'OMG' and 'Without You,' his hit with David Guetta.

The cast of 'Glee,' including Darren Criss, Naya Rivera and Amber Riley, also took the stage from the screen. Criss rocked an acoustic guitar for Rivera's vocal performance of 'Valerie,' and Riley took the spotlight for a cover of Christina Aguilera's 'Beautiful.' Criss sat behind a piano for 'Not Alone.' A choir joined him for the tail end of the performance, which was one of the most moving of the night.

Perry was the headliner -- aside from the P.O.T.U.S., of course -- and she, as usual, rocked a patriotic outfit. Perry donned stars, stripes, red, white and blue in a onesie and sparkly stockings. Perry also sported an Uncle Sam-style hat, which she tossed to the tykes in the audience. She seemed to still be struggling slightly with balancing choreography and belting, but she's improved significantly since she first began incorporating dance moves into her live sets.

Watch the 'Glee' Cast Perform at the 2013 Kids Inaugural Concert

Watch Katy Perry Perform 'Teenage Dream' at the 2013 Kids Inaugural Concert