Blake Shelton may need to brush up on his wife Gwen Stefani's discography. Shelton, 45, made an appearance on "The Kelly Clarkson Show" recently and filmed a segment in which he paired up with his fellow "The Voice" alum Nick Jonas to play against Kelly Clarkson and John Legend for a game called "Throw Me a Line." For the game, a disembodied voice would say a line from the middle of a popular song and the singers would have to buzz in and sing the title of the song.