Now about my observation on the different schools and teachers....I always approached teachers with this in mind: No one is perfect, learn as much as you can from everyone....but do not get blind....not everything works for everyone".
I will only talk about the positive sides of things as we are not here to bash on people.
Maurice Andre....well not much I can say that people don't already know. He is a one of the most wonderfull human being I ever met. Never said anything in a negative way, always trying to find something positive about people's performance and then giving constructive ways to help with the things that needed to be better. He always practiced every instrument (Bflt, C, eflat, pic) every day...even for a short time. Music has to sing.
Eric Aubier: He is really impressive with Bflat and C trumpet. French repertoire is his TOP side. I remember in lessons when he would get ready to perform Tomasi, Jolivet....He would play one movement between each students....about 10 times in one day...for me, I would be dead after 2 ....but he got better every time and the last one was the best. For him flexibility is extremly important and would often make us play parts with one hand to release some of the pressure on the lip. You know you can really play Jolivet 2 when you can do it with one hand.....give it a try
We almost never worked on orchestra repertoire during my 4 years...well ok maybe once when the Conservatory's orchestra was having audition for the year...and that's it.....not because He can't teach it (he played orchestra for a long time with the Paris Opera) but he never spent the time on that. All lessons are class lessons, everyone there, sitting and listening to everyone play. Starting with about 1 hour of warm-up and routines, then solos.
Guy Touvron:
For me, I really loved his approach of piccolo trumpet, and classical repertoire. Being from the same teacher, his approach was quite similar as Aubier but with a different idea of style for solos.
David Hickman:
Well, he is one of the most influencial teacher for me. I learned the most from him, not only with my playing but with the history of the instrument, orchestra repertoire, chamber music.....and more. For him, I believe that music is never about the trumpet alone but about the ensemble sound. When he played the brandenburg, he never overblow it., always balance with the others....hard thing to do that high against violin, oboe, and flute.
There is a lot to say about his teaching but a good starting point is his 5 books on technique, sound.....that can be found at Robert King.
Wolfgang Bauer...for most american he is unknown. Young teacher. Won the ARD Munich Competition, was principal trumpet with Reinhold Friedrich in Franckfurt, taught in Basel, and Stuttgart. People should really look into his recordings..... great player and really nice teacher. He introduced me to Lechner trumpets....great instruments. I was really young when I took lessons from him, but want to go back someday to get more.
The latest teacher I have worked with is Dr. Tarr. since last year I am going to germany to take lessons with him. Just bought a baroque trumpet....and learning how to play it (not as easy as people think). I had a great time with him. He is really open minded and will give you different ideas and ways to play music but always letting you come up with you own style.
This a short list of comments but I did not want to put too much too fast
JC