Good question.
I remember reading that James Joyce once sought acknowledgent amongst close friends that his famous novel Ulysses was as good as a work of music.
He didn't get it.
What about that Nietzsche quote?
"Without music, life would be a mistake."
It would seem as if there is something almost supernatural about the power of music and it's ability to influence the human mind.
Perhaps it's better if we never find out just what it is?