I almost always have a solo program of some sort that I'm working on in addition to my orchestral concerts. And I have occasionally needed a new piece for a student and had nothing on me besides my own music - so sometimes I will teach a piece I am simultaneously working on myself.
I don't like it. For one thing, it can be hard for me to hear another person's interpretation when my own is so vivid in my head. So I might correct the student's phrasing to mine instead of listening for and accepting the thoughts they have about the music. For another, I don't like showing them up by performing a work that they have in progress. It just feels mean. Maybe it doesn't make them feel bad about themselves, but I can't help feeling a little guilty.
But I'm having a great time right now. I'll be performing Eric Ewazen's concerto, Down a River of Time, with the Notre Dame Symphony Orchestra in November, and I have two oboe performance majors at that school. The conductor's suggestion was that they should both learn the piece, too.
I was hesitant at first, obviously. But I am very impressed with the way he is handling this. My students will play the piece with the orchestra in rehearsals, which obviously is great for the strings as they learn it. How much fun would it be to rehearse concertos WITH SOLOISTS every afternoon, rather than patiently counting through bars and bars of meaningless accompaniment? He is planning to have each of them record it in the final weeks of preparation, which is fantastic for them. I didn't come out of college with a recording of myself playing a major concerto with orchestra, but they will. When they actually hear the performance, they will know all the ins and outs of the piece, and be extremely educated listeners. This is a win-win-win situation. It wouldn't have occurred to me, and I give full credit to Dan Stowe for it.
And it's great for me, too. Each student has a very different approach to the piece, which is fun for me to hear, discuss, and consider. I haven't started yet on my own full-scale preparation (obviously I've played it several times before) but in teaching it I am doing a lot of analysis. I am honing my own plans and reconsidering some phrases that I hadn't previously put a lot of thought into. Having to put my own musical intuitions into words is, as always, extremely valuable for me. Generally, once I can articulate the problem or the solution or the story, solving it on the oboe is the easy part. Making a coherent plan is the challenge, and right now I'm working on that off the oboe - or at least off my oboe - and feeling a lot of benefit.