Washington is about to get glee-ful. First lady Michelle Obama has invited the cast of the hit high-school singing show Glee to perform at the annual White House Easter Egg Roll on April 5. The first lady and daughters Malia and Sasha are supposedly big "gleeks," and the producers did some last-minute rescheduling to honor the request. The hit Fox comedy's cast—which belts out a mix of show tunes and pop—will probably help the first lady with her "Let's Move" initiative, meant to encourage youngsters to become more active to battle obesity. Glee The Music Volume 1 just debuted at No. 1 on the U.K. album charts, topping Lady Gaga. No word yet on what the cast will be singing.