The people at Improv Everywhere decided to surprise a lucky family in New York City with the most amazing Christmas carol, including a 20-person brass orchestra, a 13-member choir, fake snow, and even Santa Claus shows up. You might recognize the song by Karen O "Marshmallow World" from the Target holiday commercials. The video "Epic Christmas Caroling" is #trendingUP and you can see it now, on The List. www.TheListTV.