Creepy/Horror setting music?

Behold the Darkness by Medwyn Goodall is a nice one. 

I don't find this to be very creepy, just a little bit.  There is some tension to it, but I believe I've heard creepier.  I think accompanying a movie scene with some arresting visuals, it would do the job.  OP mentioned playing a horror game, I think it will add some air of suspense.

Let me think about it and I'll try to come back to this thread with a contribution.  Great find, though, I will try to acquire this song immediately.

Where might I have heard this before?

Lustmord's got some really atmospheric stuff.  Some of it more musical than others, but IMO fits the bill.  I like horror OSTs, and usually they're prog rock, but the problem with using them for creepy effect is that some passages are very much rock.

Lalo Schifrin did the Amityville themes. Again, kinda creepy, more musical.

EDIT: Just had another listen to Exorcist II OST.  Morricone killed it.  I recommend.

What about some dark ritual ambient?

I would say "Ghosts I-IV" might be a good ambient/indstrial album for your needs. It has some excelent creepy-slow tracks and also heavy ones, in case you want to change your pace.

Without a doubt, this is the scariest music I've ever heard.  Check the rest of the thread too.

http://www.head-fi.org/t/510954/frightening-music#post_6914771

http://www.youtube.com/watch?v=ipzR9bhei_o

Check out the morgue..THE MANCHESTER MORGUE for plenty of horror soundtracks and links to sites with just as wonderful horrifying audio works-

http://the-manchester-morgue.blogspot.com/ 

Nice, some of this stuff must sound great on high-end gear :D

You may or may not be a classical fan, but if it's creepy you want, you must check out the symphonies of British composer Humphrey Searle. If you know the original B/W move "The Haunting" and like it's creepy soundtrack, well -- that's Searle. The symphonies are similarly done. Very weird, scary, and definately  Halloween-worthy. I've used them for several years at my haunted house presentation. There's one set of all 6 on the cpo label, and it's worth every penny.

Shostakovich: 

http://www.youtube.com/watch?v=khpm7RLFnGw&feature=related

Rihm: 

http://www.youtube.com/watch?v=q7Wwn6rHoZw

Bartok: 

http://www.youtube.com/watch?v=cLtLW56TH7w&feature=related

That should get you started :)

My last post:

Some of Bill Laswell's dark ambient projects can really bring the mood down without drawing your attention to it. Shinjuku Thief's The Witch Hunter is like being smothered by somebody else's bad intentions.

Some good noise acts can scare people right out of the room if they aren't expecting it.