Danse Macabre.Op 40 by Camille Saint-saens. ( it will play after "This is Halloween")
This is one of my favorite classical pieces. The fact that it's Halloween related makes it even better. If you listen, the song starts with the clock tower chiming 12 times. Then all the spooks and night creatures begin to emerge. You'll hear ghost wailing. the Rattle of skeleton bones. The cackling of witches working over a cauldron. They begin adding things to the cauldron. Toward the end of the piece you'll hear the potion erupt in a profusion of flames and smoke. The witches laugh and howl. Then the rooster crows the coming of morning and all the spooks retreat. The song is so much more enjoyable if you know the story.