That's such an interesting thought. I've played some procedurally generated dungeon games in my time and I've always thought it was interesting to have a new experience but there was always that nagging feeling of aimlessness.

So in order for a machine to be able to craft an interesting narrative for a human, I think it would need to take into consideration the temporal element of how humans consume things and how that impacts the experience.

In a dungeon, that's when you go down ten different dead ends and you are losing interest.

In music that's probably a long drawn-out melody that ends abruptly, like what you're talking about.

How would something beyond that be modelled in a program, though?