Background music?

Anyone know the first use or derivation of "woo woo" as used to describe something that is flaky ("New Age woo woo"), spooky, odd ...? Thanks. JAL

I don't know the first use. I think it comes from the eerie, suspenseful music used in movies and TV programs about little green men and the like. Just a guess. "Woo-o-o woo-o-o" is about how people sound when imitating that instrumental music vocally.