All real art has a vision behind it. Characters take on a life of their own, paintings turn out differently than you planned. You can’t go against this vision without completely changing the work, and probably making the work less believable.
Dorothy Sayers wrote an interesting book called “The Mind of the Maker”. In it, she uses her experience as the creator of novels and plays to imagine how God the Creator works. In my favorite part, she says that Christians always come up to her at parties to suggest what a testimony it would be if Lord Peter Wimsey got saved. Wimsey is the main character in her famous murder mysteries. She replied that Lord Peter is an old-fashioned liberal, and would be embarassed at the suggestion. “But can’t you make him do it?” No, not without violating who he is, she replied. An illustration of what free will means.
It sounds weird to say that art has a life of its own, one that you must not violate. But it’s a useful attitude for artists. Every artist has to conform herself or himself to that vision within the work. You can choose to sing a song jazzy or reverent or brassy or sensitively. But it isn’t an arbitrary choice. It depends on the nature of the song. You may have several options, but some are more true to the work than others, so you reject the others. An actor must let the character flow out of him. The writer must do that too, in a different way. It’s probably related to incarnation. God didn’t create symbols or themes or ideas or models; he created complete human beings who are more than the sums of their parts. So maybe the artist need to pursue the work until something like an incarnation takes place.