R&B superstar Mariah Carey joined U.S. Tv host Jimmy Fallon on his talk show LATE NIGHT WITH Jimmy Fallon on Tuesday (05Dec12) to perform a unique version of her festive classic All I Want For Christmas Is You. The couple and Fallon's house band The Roots performed using classroom instruments, including a toy xylophone and a recorder. The comedian previously staged a similar singalong with Christina Aguilera using office stationery.