But we did know that she loved their song 'Say Something'.
Then today out of left field, Christina took to twitter to tell us exactly what she would performing.
Love #SaySomething by @AGreatBigWorld. We recorded it together & performing it live on @NBCTheVoice next week! xo http://t.co/G6j3VVWSCOThen shortly there after 'A Great Big World' tweeted:
— Christina Aguilera (@xtina) November 1, 2013
First, we will be releasing a new version of "Say Something" with @xtina and performing it live with her on The Voice on Tues. Nov. 5! AHH!!Have you guys heard the track?
— A Great Big World (@AGreatBigWorld) November 1, 2013
Check it out: