In case you haven't heard, Christina Aguilera and T.I. have joined forces to release an unbelievable track called "Castle Walls." Fans and critics have instantly fallen in love with the song. "We’re loving this tune," exclaims AOL's Idolator, "a bright spot for both T.I. and Xtina." Read up on Idolator's "Castle Walls" featured here, then listen to the track below!