your soul.
take jimi hendrix for example. the sounds he made with his guitar was how he was feeling at that time.
when we hear music, it sounds the way that we feel (if that makes any sense).
music isn't words, so we can't read how we're feeling. it isn't a picture, so we can't see how we're feeling.
it's sounds. we hear the way that we feel, and that's what makes it so beautiful.
when you find that one song that you love, and can just listen to all the time, its like there's a connection between your soul and the music. it just feels right, like nothing can go wrong.
that's as close as i'll get to explaining why i like music though.... i think its really inexplicable, no matter who you are.