Terrapin_Station

What determines it is a combination of nature and nurture, which is different in each individual's case. And nature and nurture are both typically complex enough in each person's case that it can be difficult to predict whether an individual will like or dislike something, even if you know them fairly well.

Anyway, here's my attempt to generalize what I'm most attracted to:

What I like best, in general, is music with quirks, delivered via material that has at least some roots in the traditional and at least slightly sophisticated melodic and harmonic craftsmanship reflected in pre-rock era pop music. I also have a strong attraction to anything with funky or "grooving" rhythms. The above doesn't mean that the music has to be pop. I just want it to have some roots in the melodic and harmonic craftsmanship that pre-rock pop exemplified. (Think of standards like "Bewitched, Bothered and Bewildered".) I'm not really that genre-oriented. I'm just quirk-(and groove-)oriented as above. Usually the further afield something moves from some combination of those three factors--quirkiness, melodic and harmonic sophistication with some structural relation to traditional pop music, and funkiness/groove-orientedness, the less interested I am in it. There are exceptions--for example, some ambient music is among my favorite stuff, but that's generally the key to whether I'll like something and just how much I'll like it.