One of my all-time favorite memories about the Halloween season, actually originates from my music class in elementary school. It is one of my earliest memories of learning about classical music. We studied Mussorgky's : Saint John's Night on Bald Mountain. Though the intricacies escape me, it's basically about how the witches gather together to celebrate their sabbath and call forth the Black God : Chornobog. The man who witnessed this worship service of the witches, saw Satan himself. When morning came, the worship service was over, and the man who witnessed the events was left to ponder them. The outcome is ambiguous and left to the listener. I remember being swept with ranges of emotion from excitement, resolve, and of course trepidation and back to relief when daybreak came. It's an intense piece of music that captures the essence of what the spirit of Halloween is to be about.
I've also found out, that it's based on a short story by a Ukrainian author named Nikolai Gogal. Now Gogal is a name that you just expect some scary stuff from, and his short story is scary and gruesome. Hard to believe people had cognitive thought when they didn't even know what indoor plumbing was. What's even more scary is that the musical piece and the story from it, even though has a central theme too it, one would be hard pressed to find that it was actually based off of this short story.
Addendum: I had thought I had left a link to some material regarding the material, but alas I did not. So, Easter Egg hunting time folks, try to find some of the eerie left over candy from last night's Hellabaloo.