Will Ferrell Joins the Vienna Boys Choir on "Late Show with David Letterman": Watch Here!

Posted Tuesday December 17, 2013 10:58 PM GMT

He starred in the modern holiday classic, "Elf" and Will Ferrell got into that old familiar Christmas spirit on "Late Show with David Letterman" Monday (December 16).

There to promote his new movie, "Anchorman: The Legend Continues," the funny man left his '70s apparel and mustache at home this time.

Joined by the Vienna boys choir, the 46-year-old actor broke out his best falsetto for a rendition of "Christmas Time is Here."

Using the same high voice for a spoken interlude, check out Will's hilarious appearance in the player below.