The Doctor Who Christmas special is set to air today, Christmas Day, on BBC America at 9 p.m. Get in the holiday spirit with some seasonal cheer from series' main TARDIS residents. Sing along as Matt Smith, Karen Gillan, and Arthur Darvill lead a rendition of "Have Yourself a Merry Little Christmas." The clip aired in a previous episode of Doctor Who Confidential, but with the current lack of Who on TV, we'll gladly take an out-of-character cast Christmas carol.