Country- Strong Republican
Pop- Democrat
Post-grunge- Democrat
Pop Punk- Strong Democrat
Hardcore Punk- Strong Democrat
Metalcore- Strong Democrat, but with some Libertarian mixed in as well
Christian Hardcore- Lean Democrat
Christian Contemporary- Lean Republican (not Strong R since many fundamentalist denominations, mine included, are against it)
Classical- Strong Democrat
Heavy Metal- Democrat
Death Metal- Democrat
Black Metal- Strong Democrat
Post-hardcore- Democrat
Grindcore- Democrat
Emoviolence- Democrat
Christian Emoviolence- Lean Democrat
Reggae- Strong Democrat, but with some Libertarians and Greens mixed in.
Indie Rock- Strong Democrat
Electronic- Democrat
Classic Rock- About even, maybe Lean Democrat (Republican if I'm any indicator)
Post-Rock- Democrat
Classical- Democratic due to the large amount of academic/professor types that usually like classical
I'd actually say that classical is Lean R despite its intellectual bent, seeing as the largest audience is still country club olds. Go to your local symphony, and the ads in the program are going to mostly be for "active living senior communities" and trust funds. Oh, and luxury cars.
The musicians themselves, of course, are about super-safe D as can be.
So are the country club olds you mentioned.