Fandom Rivalry: Between fans of Syndicate and Nox Arcana. This is probably only going to get worse once Syndicate releases a haunted carnival album. (*Cough* Carnival Of Lost Souls *cough*.)
Nightmare Fuel: There's a darn good reason why haunt events tend to use Syndicate's music, as much of their work contains stuff that's surely to leave one frightened.
Mansion in the Mist starts off The 13th Hour soundtrack on a high note with its incredibly creepy humming-like noises mixed in with various ambient sounds. It's one of those pieces of music that can make anything come off as unsettling when played in the background.
Haunted Nursery, most notably due to how it starts with the eerie sounds of toddlers crying.