True music, I think, requires thought, imagination, and should... have no direct relation to the real world (other than lyrics, as they're different). Some music "sounds like" things in life, but while it may contain ambient noises and sound affects, "music" wouldn't be simply a recording of, say, a street, for it's entirety... It's the clever way in which our mind relates things, like majors sound happy, and minors sound sad, but aren't really anything to do with "happy" and "sad" themselves. It's representational. Like folk or classical pieces may have flutes representing birds, a slower tempo representing nighttime... It doesn't, for the most part, sound like any actual thing that exists in the real world.
But music must also have some thought and imagination put into it. If you just got a guitar, a drum, and just made random noises into a microphone, that would have no relation to the "real world", but it's just noise. There's no construction or design to it. Even rap usually has thought and construction gone into it, to varying degrees (though, not every rap track does
)
Similarly, though slightly differently, I think just simply ripping off someone's style and copying it isn't really "true" music (however it is still music), it would be kinda soulless. It needs thought and imagination, your own style.
It's just my personal thoughts, but yeah...
Edit: wait, I just realised I've posted in debate forum, I don't remember seeing a "reply" button before... Is this because I've reached a certain post count or something? =o