Mariah Carey, Jimmy Fallon and The Roots Perform 'All I Want for Christmas Is You' with Classroom Instruments

Welcome to the new pop culture world order. If you're a musician and you're on Late Night with Jimmy Fallon, you better make time to sit down with Jimmy Fallon, Questlove and the rest of The Roots to record a quirky and awesome version of one of your hits. Ask Carly Rae Jepsen. Ask Christina Aguilera. The Internet now expects this of you.

Mariah Carey didn't let us down when she appeared on Tuesday night's episode of Late Night, singing All I Want for Christmas Is You as Fallon and The Roots played along on classroom instruments. Check out the clip after the jump.