Tonight, two of Gwen's artists are shocked by the challenge of having to take on a Celine Dion song - in front of Celine, herself. Alicia and DJ Khaled are floored by the two R&B stars she paired against each other, and Luke Bryan and Blake team up t... (more)o surprisingly show two young pop artists how to work the stage. Gwen, Alicia, and Blake each have a steal left, while Adam has two - and is on the hunt.