Christina Aguilera on Keeping Up with 'The Voice' Boys Club

"The Voice" coach Christina Aguilera was sparring with her fellow coaches -- Adam Levine, Blake Shelton and Cee Lo Green -- telling "Extra's" Terri Seymour backstage on Tuesday that it's definitely tough being the only girl.

"Being the only female, you gotta hold your own against those crazy boys," laughed Aguilera. "They'll keep you on your toes. Everybody's feisty on this show, have ya heard?"

The excitement was high and the energy was raging at the first live show of "The Voice," on which the eight singers on Teams Xtina and Team Blake performed. Opening the show, the coaches sang a Queen medley. Watch!