Guess What Mariah Carey Is Singing on Justin Bieber’s Christmas Album


… "I Want a Hippopotamus for Christmas." Kidding! Yes, it's the Mariah staple — and arguably the Best Christmas Song of All-Time — "All I Want for Christmas Is You." According to the just-released track list for Under the Mistletoe, Mariah and Biebs will duet on the number (with Mariah on the high notes and Biebs on the slightly less high notes). Other observations from the track list: Despite reports to the contrary, original songs only make up about half the album, which is good news for anyone who ever wanted to hear Bieber sing Christmas classics with Usher (Their pick? "Chesnuts Roasting on an Open Fire"). Boyz II Men made Biebs do an a cappella cut of their song ("Fa La La," which we assume is a "Deck the Halls" spinoff). And, most important, there will be a Bieber cover of "Drummer Boy" featuring Busta Rhymes. Merry Christmas, everyone! This should be delightful. [Rap-Up]