Christina Aguilera - I Will Be (Acapella) - YouTube
We Are the Champions (A Cappella) [feat. Christina Aguilera, Carrie Underwood, Sam Smith, Ariana Grande, Blake Shelton, Usher, Meghan Trainor & One Direction) - Single — Jimmy Fallon and The Roots | Last.fm
Diva Devotee: Christina Aguilera Shows Ariana Grande That Volume Always Win On "We Are The Champions" A Cappella
Christina Aguilera has a special edition in honor of her 20th anniversary
Christina Aguilera - What A Girl Wants (Acapella) - YouTube