A Hogwarts Christmas
When the decorations went up, Harry noticed that they were the most stunning he had yet seen inside the school. Everlasting icicles had been attached to the banisters of the marble staircase; the usual twelve Christmas trees in the Great Hall were bedecked with everything from luminous holly berries to real, hooting, golden owls, and the suits of armor had all been bewitched to sing carols whenever anyone passed them. It was quite something to hear "O Come, All Ye Faithful" sung by an empty helmet that knew only half the words.
--J.K. Rowling, Harry Potter and the Goblet of Fire
P.S. If you're a fan, here's something new from J.K. Rowling: The Tales of Beedle the Bard. I wonder if it will ever be published for everyone to see?