Music *can* be divided into "good" and "bad" music, but, like others have said, those opinions are subjective.
If you choose criteria by which to judge a piece of music, such as the technical prowess of the musician, then this may allow you to rank songs somewhat objectively based on their difficulty. However, this doesn't mean that someone would judge more technical pieces of music to be "better" than music played by less skillful musicians. I often like simpler pieces of music better than technically challenging ones. And some people like crude music with out-of-tune singing. People like Stu.
I don't think that greater knowledge of the mind will allow music to be created that better appeases the mind, especially since many musical preferences appear to be based on culture, and cultural preferences change rapidly. I say that music in 500 years will sound different than music now, but it won't be more "advanced."