Should anything ever happen to Cher, Shakira, or Britney Spears, Christina Aguilera has got you covered. The pop star proved to be a canny impressionist during her appearance on yesterday's Tonight Show Starring Jimmy Fallon. Let's just say that the next celebrity guest to play "Wheel of Musical Impressions" really has his or her work cut out for them. The rules were simple. Push the button, then sing the randomly chosen song in the style of a particular artist. Aguilera first belted out the Folger's coffee jingle as her Burlesque costar Cher. Fallon then did a respectable David Bowie-styled version of "Grand Old Flag." Shakira and Michael McDonald also got some love, but it was Aguilera's second performance that earned a standing ovation from Fallon. Behold, a Britney Spears-inspired rendition of "This Little Piggy." The Voice judge nailed her former Mickey Mouse Club costar's breathy cooing, giving the nursery rhyme a poppy update straight outta TRL. Spears may or may not be impressed, but we certainly are.