The battle rounds begin and the coaches enlist the help of top recording artists and producers to offer their knowledge and skills as advisers. Alicia Keys teams up with DJ Khaled, Adam Levine with John Legend, Blake Shelton with Luke Bryan, and Gwen Stefani with Celine Dion. In this phase, the coaches pit two of their own team members against each other in a dueling duet. After the vocal face-off, each coach must choose which artist from their team is the strongest, and has the option of stealing losing artists from an opposing coach. Each coach has two steals during the battle rounds where their artists proceed to the knockout rounds. (thetvdb.com)