After Miley Cyrus announced her role as key advisor on 'The Voice' via a tounge-selfie, the original 'Dirrty' girl, Christina Aguilera, decided she wants in on the action! With ponytails held up high to perfection, the two pop stars have some fun on the set of the singing show. Is this a taste of what's to come with the return of Xtina on 'The Voice?' We hope so!
From Michael Jackson to The Rolling Stones to Katy Perry, see how well you know halftime history