On the Kelly Clarkson show, Kelly and John Legend went head-to-head in a battle against fellow Voice coaches, Blake Shelton and Nick Jonas, for a game of Throw Me A Line.  In this game the players hear a lyric from a song, buzz in when they recognize it, continue to sing the song, and then name the song and artist.  So how well does Blake know his wife’s music??  …well let’s just say he didn’t recognize Gwen Stefani’s Hollerback Girl lyrics.