I can see that I need to add a few extra comments to my last musical exhortation. To cut right to the chase, the answer is that yes, as “pure music,” Schonberg and all his ilk are out. Attempts to create music that fly in the face of how God (clearly) intended for music to be created are rebellious in principle. But note that I said “cacophonous all the down” and “dissonant all the way through.”
The use of cacophony or dissonance is not a problem at all. As Chesterton put it, a book without a wicked character is a wicked book. The problem is not the recognition that there is dissonance in the world; the problem is in the attempt to pretend that we can declare that the world is the kind of place where dissonance is all there is. That kind of thing is high rebellion and Christians must have nothing to do with it.
But these things can still be used appropriately — they just cannot be taken as a “stand alone” appropriately. Take Berg’s Europa String Quartet — there are parts of that thing that would be a great soundtrack for a creepy scene in a warehouse down by the harbor. Set it in something else that gives it the kind of meaning that can be had in God’s good earth, then fine. But when people want to tell me that this is the way it is all the way through, then forget about it. Why should we receive in a piece of music a worldview which, if we read in a book, we would throw it against the wall?
Cacophony is not music that is loud or boistrous; it is more random and aimless than that. Think of the first twenty-five seconds of Magic Carpet Ride by Steppenwolf– that is cacophony. But in that case it used well precisely because of how it then resolves. Distortion for the electric guitar can be fine also because that is simply the electronic modification of the timbre of the instrument — it does not lose the tonal center. For another example, wise composers know how to use dissonance in a way that “crunches” and then resolves.
The kind of thing that I had in mind in the previous exhortation was the kind of irritating alternative music that is far enough away from the musical center to appeal to rebels, and not so far away that the radio audience diminishes to about sixteen really cool people. The trick for these rebels is how to have the philosophy of the Schonbergs made palatable enough for the masses. When we get to that point, we will have at that point developed our orc music.