american gothic isn't inherently horror. i recommend checking out the links provided, feeling what those staples in the genre are, and then proceeding. you can make as many entries as you want, but if you want to do lots of music entries, i might recommend an album or compilation for simplicity purposes.
Yeah, I've noticed that American Gothic music covers actually quite a bit... Most seem to be a hybrid of country/metal, while some songs that are southern american gothic horror has a more depressing, ambient atmosphere from what I've heard so far, so my music I make is probably going to sound a lot like southern american gothic music.