Oooohhh- Halloween is nothing here, Mardi Gras is the big lynchpin of the cities' culture. And the big gay conventions aren't at Halloween, I suspect those were just regular natives and some houseguests. LOL New Awlins people all liked to play dress up long before we had a big gay community, but they've really kicked it up a notch.
Can you tell I'm working furiously on my own costume today?
Which actually segues back to the topic nicely. New Orleans music is full of weird songs about voodoo, death, dying, ghosts, "The Voo Doo Queen of New Orleans" ect., although time is a little short to get your hands on it. Go to <www.wwoz.org> , The Greatest Radio Station In The Universe- all volunteer and nonprofit. You can listen over the web, and you can Email or call with questions. If you don't like it, give it an hour and it'll change.
Several things that come to mind- "St. James Infirmary", there are a zillion fantastic recordings of this classic dirge, (jazz funeral march classic) though an easy one to find might be Kermit Ruffins "Swing This" CD. Also, "Walk on Gilded Splinters" by Dr. John, very spooky and on his the very best of album. Both these records are worth the cash, lots of year round listening pleasure. And if you have any Hendrix, he did a lot of old blues songs with appropriate themes. Some of his counter tempo might be tough on cadence though.
Iggy Pop- amongst all the weirdest songs ever written he put out, one of the strangest is on "The Contino Sessions" CD by Death In Vegas; another album worth buying for spin tracks and driving music, but the song is both creepy and awesome, called "Aisha". Their "Dead Elvis" CD is wonderful too. Very splendiferous guitar work.
Hope this helps.
Then there's "Monster Mash". Use your own judgement there.

Lizzy