Some of the fighting about music reminds me of how I used to get so mad, when people criticized my liking of punk rock. Or how I'd get so mad if someone made fun of my favorite bands - I got into online arguments, and I'd get so mad it was as if I was a member of the band myself. Not that I was pretending to be, or something - it was just that I took it that personally.
Same goes for cars - I'd get so mad if someone made fun of my love for Mustangs.
I see the error of those ways now and have since stopped doing that. I think it's important to remember, that while we strongly identify with our tastes, a person's like or dislike of a band or genre, or car, movie, whatever, is not necessarily an attack on a person themselves, or their character.