Old TeleMan and wdb, that song was one of five or six. The entire show was almost 20 minutes long. Other songs were more Christmassy.
The guy has a sign in his front yard listing a radio station to tune into. You drive up in your car, turn on your radio, and set it to whatever volume you want. It's like the old drive-in movies! (His FM transmitter has about a 1/2 mile radius!)
I thought it was a neat idea, because everyone has their windows rolled up and heaters blasting. Just standing on the sidewalk, there's no music at all. I bet the neighbors appreciate that!
Here's a little more info on that light show.
DIY X-Mas Light Show