The choices and tastes of a person are a defining part of their identify. I do not believe, for instance, that the person shooting guns and listening to pop country and the person sitting in a coffee shop listening to Sam Beam are romantically capatible people.
Taste is what one finds pleasing, and there are many reasons why one might prefer country to classical, say, or vice versa (upbringing, genetics, etc). They have nothing whatever to do with identity. If you're defining yourself by your taste in music, art, whatever, then you, my friend, are leading an exceedingly shallow existence (my apologies for being so blunt).
There is definitely a lot to be gained by having similar interests insofar are you will enjoy doing stuff together, which I think is important (such that one needs to be friends with their partner, first and foremost, to be anything else). But some interests will converge and some diverge, and there's nothing wrong with that, unless you're looking for an accessory and not a partner.
My wife, for example, is an amazing person. She is a beautiful piano player, and is a highly talented and successful artist, all qualities you might be attracted to. BUT, she also enjoys laying on the couch and watching The Kardashians and King of Queens. I can't be in a room where Kim Kardashian is on TV, so guess what? I leave. I don't see it as an existential threat. KoQ I find absolutely terrible and trivial, but it doesn't inspire the level of disgust in me than does reality TV generally and Kardashians in particular. But that just shows she's human. No one has high minded ideals all the time. I play hockey and occasionally even get in fights like a high school kid while doing so. Those are things she probably finds childish and low brow about me. These things make us more human.