Totally depends on the girl. But you should talk to her about music in general and you could bring up what you like and you being passionate in your music taste could help her realise that you have an interest in music as a whole and that she is able to connect with you. If you hang out more, you could teach each other a thing or two about your own interests and that's a bonding experience that could make a girl fall for you. Personally, I'm really into house, trap and rock. And I wouldn't mind learning new things about other genres of music.
I think he can like whatever he likes as long as I can do the same. I have a wide range of musical interests and I don't want someone who will get annoyed with me if I'm listening to country one day versus classical the next. Or 60's in the morning, then 80's at night. Musical tolerance would be nice I guess.
I think that taste in music is just a bonus! For example a know a guy with a very good taste in music but other than that he's banal and boring, on the other side there's a guy I know who listens to mainstream songs (which I dislike with a passion) but he's super smart and cultured! So yeah, it's just a bonus in my opinion