Coming from a student's perspective....I have this discussion with my peers (of all disciplines) and it always incites some great discussion. The issue is, what's the point of teaching the next generation of teachers to teach a bunch of teachers...THERE'S NO POINT.
Although there are some great professors without (IMHO) adequate professional performance experience; just getting their doctorates, doing some competitions, and teaching college. The whole "military band/orchestra, teach at college, get some gigs" also just doesn't work anymore. You should consider a career as a private teacher, soloist, CHAMBER MUSICIAN, jazz freelancer, and finally an ensemble musician. There's plenty of weird ways to make money on tuba and euphonium out there, and if one fails to nail the big audition, that shouldn't be discouraging at all! I would love more than anything to be the euphonium soloist in a service band, but the odds are that I'm not! So being a "smart" university student I am trying my hardest to learn my solo rep, chamber rep, work on jazz, and even klezmer! You never know where the gig is, but the smartest students are the one who become the best possible candidates for ANY gig, not just an orchestral career. There was a graduate French Horn last year that refused to play in chamber ensembles, or groups like horn choirs or brass ensembles because he was hell-bent on "focusing on his orchestral career". In the 2 years he got his master's degree there were french horn openings in the US Coast Guard Band, the US Marine Band, the Atlantic Brass Quintet, and the Connecticut Horn Choir...but he decided not to take them. Well he's now jobless, in loads of debt, and living with his parents. He sure knows his excerpts well though! I also believe that every music major should consider double majoring in music education, or seeking graduate degrees in music education. To be honest, I really hate music education courses...but job guarantee is REALLY nice. A lot of people I know who are excellent musicians (Phil Giampetro, winner of 2010 ITEC artist euph solo comp) is teaching elementary school band now! He's using it as a stepping stone for his career as a performer.
I have no clue if any of this is relevant or if it's just rambling....but I think you bring up some really valid points, obviously from the perspective of a seasoned player. I think this discussion needs to be brought up MUCH more often.
This is my favorite quote from your post:
Others stay in school and pile on the diplomas and degrees, going six figures into debt, not developing any skill other than playing their instrument, surging forward on the hope and belief that some day they will score a plum gig and be able to pay off their loans; most never will. In either case, if they were my former students, I wouldn't feel happy about my work.



