If you live in the Washington, DC area, the first sure sign that Christmas is coming is WASH-FM. The radio station which usually plays middle of the road Adult Oriented Rock changes its programming entirely on Thanksgiving evening to all Christmas music all the time. It stays that way until Christmas evening.
I like the programming not only because I like Christmas music but because the station does try to vary the sort of music it plays. Not only do you get the normal pop radio carols but you also get old classics, instrumental pieces, and, if you catch the station at the right time or hunt ahead on the playlist, Pavarotti’s “O Holy Night” (which, for my money is the greatest Christmas song ever recorded).
If you don’t live in the DC area, you can still get the station live over the net. I recommend you tune in for a while. Christmas music is good for you.