Last night I had the immeasurable pleasure of attending a speaking engagement by Rabbi Daniel Lapin. The man is extraordinary and I highly recommend any material he puts out. His talk was about the creation of wealth, but he touched on music very briefly.
He was trying to show the difference between physical and spiritual. Spiritual, not defined as being "godly", or "holy", etc., but simply as "not measurable by machines". The doctor can tell you how tall your baby will probably be. He can tell you what skin color your baby will have. He can even tell you whether your baby will have the tendency to be thin or not. But the doctor cannot tell you whether or not your baby will grow up to be honest; he can't tell you whether your baby will be friendly or not. These attributes cannot be measured by the technology we have. They are spiritual.
So too with music. Music is spiritual. There is no machine that can listen to a piece of music and tell you whether it will make men sad or happy, or whether it will make them ready to fight or ready to dance. A machine cannot tell you that- a person can tell you that. Because music connects directly to people. We musicians just bridge the gap between emotions and sound- expression.
That's sort of the gist of it anyway.