I am trying to find scary organ music for halloween.?

Please don't say Bach's Toccata and Fugue in D Minor. I already have it and it's not that scary. I'm looking for pieces for organ that are preferably loud with dark harmonic progressions. I have some works by Messiaen, and they're just ok. Any suggestions for specific pieces or organ composers with truly scary music. Something with Phantom of the Opera qualities but not so theater-like, if that makes any sense.