If I met someone who likes Taylor Swift, loves modern rap, and has a 90s pop rock CD collection I wouldn't mind, because some modern rap is funny or catchy, and 90s pop rock was awesome (until the late 90s).

If I met someone who likes Taylor Swift, loves modern rap, and likes nothing else I would think less of them as a person. Taste in music is a part of who you are too. Most people throw musical taste into their perception of a person.