Like the drunkard looking for his keys under the street lamp, it’s easy to pay attention to the legible, quantitative aspects of a field rather than the illegible, qualitative aspects. Most of music theory is concerned with the study of notes as they can be notated. The aspects of music that can’t be notated seem to get somewhat ignored.
It’s sometimes difficult to describe to people what it is that I do when I’m making music. Some of it is about choosing the notes. But I spend probably about 50% of my time, perhaps more, working on the choice of sounds and adjusting them to get the right effect. With the Nosferatu project, I’m working with samples of real instruments. That means spending some time adjusting the dynamics to get something perhaps not realistic, exactly, but at least evocative of something realistic. And as my skills at mixing have improved, I’ve got a better sense of the way in which small tweaks to the sound can guide the listener’s ear through the piece. I might want to bring the listener’s attention back to a bassline that has been continuously playing, and a short volume boost for just the first note of the bar can do that.
In other genres, the ratio between composition and sound design is much more extreme. You only have to watch a YouTube video on neurofunk bass design to see how deficient music notation is to the task of representing timbre in music. I’d say that for those sorts of genres, we don’t really have a way to usefully notate what’s important about the music outside of the audio itself.