This week on Late Night With Jimmy Fallon, as Fallon and The Roots played toy instruments, Mariah Carey joined them, along with some children, for a rousing rendition of “All I Want for Christmas is You.” Check it out. Although now it seems like “All I Want for Christmas” is a holiday classic that has … Continue reading "All I Want for Christmas is for Mariah Carey to Sing With Jimmy Fallon and the Roots"