Those who can, do.
Those who can?t, teach.
In guitar, this maxim seems a truism. No one confuses John Williams or Kazuhito Yamashita with a great teacher. Great players usually are such because of a consistent, overriding, all-encompassing selfishness and self-involvement. In order to dedicate all of one's self to a performance, one must be able to exclude all distractions. That means the manias usually associated with guitarists (i.e. tremolo envy, scale envy, tone envy) and the solutions for those manias are not the nighttime musings of our great performers. Their teaching usually amounts to ?You know what the problem is, and if you practice as hard as I did, you will find the solution.?
A real teacher is concerned with the development of the student (in all facets). Which means that one who is spending the time getting you scholarship money, finding gigs for the department, thinking about music for you to play, exploring performance opportunities and helping file your nails probably does not have a great deal of extra time to spend practicing. Such teachers, more concerned with their students than with themselves, thus sacrifice their own skills in service of the students.
But Stephen Robinson, it seems, has found the key to balancing the two (or perhaps a great, big box of No-Doze). His career as a teacher is well known. He founded and runs the guitar department at Stetson University, and his yearly International Guitar Workshop attracts artists from around the world. At the same time, he won a bunch of competitions, recorded a score of CDs, and continued touring regularly.
My favorite of all of the recordings I reviewed was, surprisingly, his duo recording with flute player Angelita Floyd. Perhaps, though, the key to his balanced musical life is held in this recording. Robinson's playing on the Sturm und Drang tracks of the Piazzolla Histoire du Tang is sensitive to Ms. Floyd's playing but at the same time infused with its own sense of direction. That said, anyone who has played these pieces knows that there is great deal of virtuosity, a virtuosity which Robinson has in spades. With the arrangement for flute and guitar of that other concerto by Rodrigo (gentilhombre) one sees in music Robinson's self-effacing ethic. A score that had the guitar as central becomes a score where the guitar supports and nurtures. By design the guitar is taken out of a central role, but its job is no easier, simply different. What once was a score selfishly designed to show off the guitar has now become one where the guitarist selflessly supports the flute.
What you have with Robinson is a player who has, in my estimation, married the two opposite ends of the guitar experience (teaching/performing) by finding a way to express the impetus for both simultaneously. It's a remarkable feat and one to aspire to.