The website says:

"Halloween is meant to be scary, right? Year after year we dust off the old silly 1950s and 1960s novelty records. While they are fun, they not at all frightening. Oddio Overplay put the challenge to musical artists the world over to create Halloween music that is "frightening, damaging and disturbing." No "Monster Mash," instead creepy soundtracks to a fiendish Halloween. They succeeded with CALLING ALL FIENDS! Some of these pieces will creep you right out of your skin."

http://www.oddiooverplay.com/ears/fiends/index.html

Spooky stuff, and would be great for background music for bizarre effects. Only trouble is, I can't find any info on performance rights. It's free to 'download and enjoy'. If you'd like to use it in your act, I suggest you contact Oddio Overplay for licensing details.

Performance rights won't be an issue for the most part- all these tunes are released under the Creative Commons license 2.5, which is roughly the artistic equivalent to GNU Open Source.

http://creativecommons.org/licenses/

There is some variance however from artist to artist or tune to tune in the license, so in some cases you can do whatever you like, in others, you can't make a derivative work or use the tune in a commercial venture. Be sure to check which version of license each song has so that you don't break the rules.