If the words "science fiction" scare you and don't really put you in a holiday mood, just give me a moment to try to convince you to give this one a try.
Aliens have landed in Denver. They haven't made any demands, tried to take over, or even brought greetings from another world. All they do is hang around the DU campus and glare. Glare like that relative you have that doesn't approve of anything. A commission composed of linguists, anthropologists, botanists (in case they're plants), astronomers, aromatherapists, religious leaders, and scores of others has been appointed to try to find a way to communicate with the aliens. Every known language, living and dead, has been tried, along with music, colors, symbols, and mathematics. Nothing but glaring. When some commission members take the aliens on a field trip to the mall, the aliens finally DO something. They sit down. What are they responding to?
While most of the commission is trying to figure this out, one member, Meg, thinks she has a clue. The Christmas song the mall had on at the time was All Seated on the Ground. The song said to sit, the aliens sat. But why did they respond just to this? Her discovery is the start of an adventure involving a local choir director, hundreds of CDs (who knew that so many Christmas songs had dangerous things like mayhem and death in them?), and a race to communicate with the aliens before they give up on humanity and leave. The end result is in the true holiday spirit. So, if you're looking for something a bit different, give Connie Willis a try. And share your favorite season's reading in the comments!