Music One Direction and Jimmy Fallon Sing a Christmas Classic With Classroom Instruments! By Philiana Ng 9:58 PM PST, December 22, 2014 NBC Directioners, here’s an early Christmas gift for you.Two days after their Saturday Night Live duties as the musical guest, One Direction’s Harry Styles (who had a dance party with Kristen Wiig), Niall Horan, Zayn Malik, Liam Payne and Louis Tomlinson dropped by the Tonight Show for a special holiday treat!The fivesome took on the holiday classic, “Santa Claus Is Coming to Town,” accompanied by Jimmy Fallon and The Roots with only the use of classroom instruments.PICS: One Direction's Must-See Selfie!Dressed in festive holiday sweaters (Harry’s takes the cake), four of the five 1D guys get their moment to shine in a rockin’ version of the Christmas staple.But we have some questions: Where is Zayn’s solo? Why did Niall get more lines than the rest? We may never know.VIDEO: One Direction Gets Waxed for Madame TussaudsMeanwhile, loyal Directioners made some pretty impressive connections from 1D’s early days to now.FOUR YEARS LATER AND ZAYN IS STILL SMASHING IT ON THE TRIANGLE pic.twitter.com/t5lr033zRJ— LIAM THAJDKYOU!!!200 (@zaynderwall) December 23, 20142010 ZAYN “I CAN PLAY THE TRIANGLE” 2010 HARRY “I CAN PLAY THE KAZOO” 2014: #WeAreAll1D#WeAreAll1DFollowPartypic.twitter.com/jNOhxqNOID— One Direction (@zarryyl) December 23, 2014 Earlier this month, Harry fanboyed over Sir Ian McKellen and back in October, he and the guys helped a fan propose to his girlfriend at one of their concerts! They also met the Duke and Duchess of Cambridge, William and Kate, where Harry congratulated the expectant mom on her pregnancy. Watch ET's report below!And here's hoping we get to see more 1D adorableness on One Direction: The TV Special, which airs tonight at 8pm on NBC!