Over the years I've developed some theories about music. They usually come to me as I'm listening to something I particularly like, and I've just now started to jot them down. I'll edit this post if anymore come to me.
I could come up with a no doubt endless amount of metaphors to describe my thoughts on a particular aspect of music--exploration--but for now I'll just stick with this one: essentially I view music as an endless road of wonder, where, at the end is a beautiful and mysterious cloud of unexplored territory.
Music has to move me in some way, whether it be the somber and bleak tone of Red House Painters, or the hyper-literacy of the Decemberists and Morrissey (the Smiths) that makes me have a complete nerdgasm.
I always try to have an open mind, but I also accept that there are certain "artists" that I don't need to listen to much of to determine that I don't like them. These would be Avril Lavigne, anything from High School Musical, 50 Cent, etcetera.
To date I have not found one single genre of music that doesn't (for me) have a single worthwhile artist belonging to it. Rap? A Tribe Called Quest, among others. Death metal? Opeth. Jazz? Miles Davis, of course. Pop? Regina Spektor does it for me. Acoustic? Nick Drake is the man! You get the picture, I'm sure.
More will follow, no doubt.