I am, without a doubt, a very tough teacher. But do the students really want to pay me money to ignore their problems? Or would they rather we solved them? I had one young student--nice fellow, but just a bit oblivious. He was doing a pretty good job with a Ponce prelude, but he had learned one note wrong and even though I mentioned it every time, he just could not seem to get it in his head that he had to fix it. So finally, after about four or five weeks of this I said, "if you don't correct that note, do NOT come back next week." Then, he got it. But perhaps this is just like Sisyphus, rolling the rock up the hill over and over. Some stuff students will absorb and other stuff they just won't. I just can't give up on trying even if occasionally I use shock tactics. It is not that I don't like my students, I do!! And I want to build their confidence and technique and musical understanding. But my way of doing that is to make real improvements in their technique and musical understanding. That will certainly build confidence.
So how does aesthetics play a role? Well, another problem the student had, and the main reason he came to me, is that his right hand is seizing up from playing with excess tension. The ring finger is starting to shut down because tension is immobilizing it. I think it is neurological, not physical. So, I am working on ridding his right hand of excess tension. Of course, tension in the hand shows up immediately in a thin, harsh, naily sound. So I showed him what a good sound was and how it was based on a relaxed hand and good follow-through in the finger movement and pointed out how, if he really listened to the sound, it would always tell him if he was relaxed or not.
But how I am thinking of it is more that aesthetically, we want to achieve a good sound, so that is why we want a certain right hand technique. In other words, the goal is an aesthetic one and technique is just the means.
How I teach is I try to activate and intensify the student's aesthetic sense: look for a good sound, a good use of dynamics, an understanding of phrase and so on. It is all aesthetic! The only other guitar teacher I have noticed using a similar approach was Oscar Ghiglia. But I'm sure it is much more widespread than that.
A good deal of guitar playing is aesthetically poor. One indicator is the harshness of the sound. If you are hammering and beating on the guitar, you are not thinking aesthetically. Unfortunately, much flamenco seems to be little more than rhythmic pounding on the guitar:
Here is what a really good sound is even in a so-so live recording:
And yes, also good dynamics and phrasing...
To sum up, how I teach is to activate the student's aesthetic sense and then help them find the techniques to realize the aesthetic goal. It usually works to some extent.