It wouldn't be Christmas without Jimmy Fallon's classroom instruments — and this year it was boyband heartthrobs One Direction who joined Fallon and the Roots for a wonderful festive sing-along!

Decked out in their finest Christmas sweaters, the "Story of my Life" hitmakers got into the festive spirit with a rousing rendition of "Santa Claus Is Coming to Town," each of the 1D hunks taking a different classroom instrument for their musical mash-up.

Harry Styles, wearing a fetching red sweater emblazoned with a glittering Christmas tree, kept beat with a big bass drum while Niall Horan, dressed in elf-green, played a yellow banana-shaped instrument.

Fallon took the first solo, leading the way while his chart-topping boyband and Tonight Show house band accompanied his singing efforts. The 1D boys then took turns to sing parts of the seasonal song (Zayn Malik on the triangle, Liam Payne playing the coconuts, and Louis Tomlinson on a pink tambourine).

In recent years, Fallon's Classroom Instruments has become somewhat of a holiday tradition. In 2012, Mariah Carey joined the talk show host in festive figure-hugging red dress to sing a stripped-down version of her classic hit "All I Want for Christmas is You."

Watch the whole performance above and be sure to catch One Direction: The TV Special airing tonight at 8 p.m. ET on NBC!