Prepare to wear out the repeat button. “The Sing Off” champs who have taken the a cappella world by storm majorly step up their game with their latest cover of A Great Big World and Christina Aguilera’s “Say Something.” With the inclusion of just their voices but a new addition to the team (the cello) in this cover, the group blows this cover out of the park with their haunting, yet serene take. Check it out below and let us know what you think!