In the main, cavernous room of the Washington Convention Center, Michelle hosted the Kids Inaugural Concert, thrown for and in honor of the children of military families nationwide, said The Hollywood Reporter.
The event was officially emceed by 'America's Got Talent' host Nick Cannon.
R&B star Usher led off the concert with a string of his biggest hits. The Grammy-winner was greeted by dancing children of all ages; there were four-year-olds standing on their chairs, humming along and bending their knees, often holding hands with their mothers.
Several cast members from 'Glee' -- Darren Criss, Naya Rivera and Amber Riley -- earned their own raucous cheers, as they performed an acoustic song each. Riley's rendition of Christina Aguilera's 'Beautiful' was a particular hit.
Perry took the stage in her trademark Uncle Sam-style corset, with a full band and backup singers behind her. She sang 'Teenage Dream', 'Part of Me', 'Wide Awake' and 'Firework'.