Aaaand Here's Your Adorable Thing For the Day

You may remember Jimmy Fallon and the Roots playing classroom instruments with Carly Rae Jepsen a few months back. Well, the late night team is back at it again with a very adorable rendition of "All I Want For Christmas Is You." Mariah Carey joins to sing her song, and still has an incredible voice. There are also some very cute cameos you'll find at the bottom of your screen. If you don't like this video, well...nice to meet you, Mr. Grinch.