See the video that's going viral this Holiday Season!

The a cappella group Pentatonix who won the third season of NBC's ' The Sing-Off', has released this video of their version of K.K. Davis' 'The Little Drummer Boy', first recorded in 1955 as 'Carol of the Drum'.

From Wikipedia, the free encyclopedia:
"The Little Drummer Boy" (originally known as "Carol of the Drum") is a popular Christmas song written by the American classical music composer and teacher Katherine Kennicott Davis in 1941.[1] It was recorded in 1955 by the Trapp Family Singers[2] and further popularized by a 1958 recording by the Harry Simeone Chorale. This version was re-released successfully for several years and the song has been recorded many times since.[3]
Pentatonix is an a cappella group of five vocalists, Scott Hoying, Kirstie Maldonado, Mitch Grassi, Avi Kaplan and Kevin Olusola, originating from Arlington, Texas.
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