Country - strong gop
Pop - depends on sub-genre; Taylor Swift - strong GOP; Katy Perry - leans GOP; Madonna - leans Dem; Lady Gaga - strongly democratic
Post-grunge - lean GOP
Pop Punk - lean GOP
Hardcore Punk - lean GOP
Metalcore - GOP
Christian Hardcore* - strong GOP
Christian Contemporary - ridiculoulsy GOP
Classical - toss-up
Heavy Metal - GOP
Death Metal - scary nihilistic rightwingers
Black Metal - scary nihilistic rightwingers
Post-hardcore - GOP
Grindcore - GOP
Emoviolence - GOP
Christian Emoviolence** - strong GOP
Reggae - strong Dem/green
Indie Rock - lean Dem
Electronic - lean Dem
Classic Rock - GOP
Post-Rock - GOP
*It is worth nothing that there is actually a Christian "sound" in hardcore that is slightly different from non-Christian bands, so there is a musical differentiation, not just lyrical content. It's more moshy and has a far higher percentage of songs consisting of breakdowns.
**This includes about six bands total, none of which are active today.
mostly white people music, no? Given the demographics, I would say most of the above probably lean GOP.
What about rhythm and blues, jazz, gospel, motown, rap, Spanish pop, salsa, world music, and K-pop?