Musical Advent Calendar, Day 19 and 20 - Jimmy Fallon, The Roots, One Direction and Mariah Carey

"Santa Claus Is Comin' To Town," Jimmy Fallon, The Roots and One Direction



"All I Want For Christmas Is You," Jimmy Fallon, The Roots and Mariah Carey

Whether Jimmy Fallon will be able to sustain the good cheer that defines his "Tonight Show" over a period of years remains to be seen, but for now it's a hoot to watch.  And few of his bits define that mood more than his "Musical Numbers on Childhood Instruments" videos.  Here are a couple of classics.