The battle rounds begin and the coaches enlist the help of the music industry's top recording artists to offer their knowledge and skills as advisers. Miley Cyrus teams up with Joan Jett, Alicia Keys with Charlie Puth, Adam Levine with Sammy Hagar, and Blake Shelton with Bette Midler. 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 will proceed to the knockout rounds. (thetvdb.com)