I have to say neither. I think there is no answer to this question.
Take Rap for example. I do not like rap music. I hate it and I want it to suffer, suffer for a long time. I really hate rap. No only is it so annoying and boring but it also makes me angry, angry like a boiling kettle. This is really how I feel.
Anywho looking at this you would think of me as having an Objective look at music. This is wrong.
While my opinions of rap are now set in stone this was not always the same, there was a time (read: 12 years old) when I could have became a fan of rap and have my undying love for rap set in stone. What I am saying here is that it is possible for our music tastes to change thus making them subjective. But if your music taste is determined by popular culture than you are usually also told what is good, at the same time telling you what is bad. For example rap fans thinking that metal is lame and vice versa.
While most will think this makes music both subjective and objective I think the opposite. This is because the two will negate each other. How can you think that all music is good while also having the music you listen determined by something out of your control.
Granted there are people who form there own music choices, this makes music subjective for them and there are people who only listen to one type of music despite whther it is popular or not (classical fans come to mind here).
You become Objective by a Subjective society pretty much. You have the chance to like many differant types of music and then you become one of those that only like one type of music (objective).
This is just my opinion and has obviously been altered by my life and the things that contain. This is also why I think it is neither because if the answer changes from person to person that makes the answer nothing. There is no answer.