Christina Aguilera Joins New Duo for Powerful New Video

On a recent episode of NBC's The Voice, coach Christina Aguilera joined newcomers A Great Big World for a performance of the duo's new ballad 'Say Something'.  The pairing went so well Aguilera actually went back into the studio to re-record the track as a duet.  The accompanying music video is just as eery and heartbreaking as the song.