Over the Summer, Jimmy Fallon, Questlove, and the rest of The Legendary Roots Crew teamed up with Carly Rae Jepsen to bring you one of the viral-ist of the viral videos when they performed the second most popular song of 2012, "Call Me Maybe", with the help of some classroom instruments. Now, the gang is back, except Christmas is approaching, so they traded Carly Rae Jepsen for Mariah Carey and performed "All I Want for Christmas Is You". Move over DMX, because this just might be the best holiday song of 2012.