Hm. It might be hard for me to even find someone who had horrific taste in music. Part of it is that I like many different genres and can at least try to see the good in some other genres that aren’t my favorites. (I dated a big-time Metallica fan for a while; I came away with an appreciation of their work and the ability to leave “Enter Sandman” on the radio when it’s playing.) Part of it is that I hang around a lot of musicians, especially singer/songwriters, and that might limit the possibility of meeting someone whose taste just wasn’t compatible at all with mine.
What would be “horrific”? Um… probably top-20 pop (I think they’re calling this “Contemporary Hits Radio” now) and the more negative forms of rap. I’d have a hard time if a friend or partner had to play that around me all the time. I’d like to mention that I’m sympathetic, and I don’t play bluegrass music around other people all the time, myself.
What’s maybe more frightening, in a way, would be finding out a potential friend or partner didn’t like any music at all and didn’t see the point in it. That would probably limit my involvement, because I just wouldn’t understand. As cliche as it is to say this, music is just too central to my life. I probably couldn’t really be friends with someone who was totally indifferent or antagonistic to music. It wouldn’t matter how good-looking or rich the person is. (Probably.)