My problems are (guess what?) upper range and stamina and his position is basically that these aren't problems. He'll assign me something I can't play, I try, I practice, a month later, I still can't play it - and I'm not quite sure where this leaves me. He tries super hard to be encouraging and optimistic - he would rather I go for a note and fluff it than not try. I'm fine with trying. I don't like to say 'I can't' - but I really can't! I can't play a high A.
I'm wondering if it's a known technique among brass teachers - just be super encouraging and optimistic and keep them at it and they'll improve? Or if I'm being particularly hard on myself as I know fine well which note I didn't play (ignorance is bliss). Or if he's confusing me for a much better player on account of the fact I'll play an etude in F#maj and not complain about the E#'s.
Try imagining you are teaching a pupil piano and they can't manage a particular technique even after a month of practising. What would you do? Presumably you would first of all try to identify exactly where the difficulty lies and what is causing the problem. Then you would choose a suitable exercise to tackle the problem, demonstrate it to the pupil, have them try it, make corrections where necessary and assign the exercise to be worked on during practice sessions. The pupil would return the following week and you would ask them to play the exercise again to see what progress had been made. You would then continue in this manner until the technique was well on the way to competency.
Is this happening in your trumpet lessons? Are you being given appropriate demonstrations and exercises during the lesson? What sort of studies are being provided? Has your range gradually been built up or are you just expected to get there somehow or other?
It's hard to tell from what you have written whether the teacher knows full well that these are problems which require a lot of time to be overcome and so is trying to get you to "forget" about them while you gradually improve as a player or whether he maybe doesn't know exactly how to help you to overcome them.
I have been learning horn for two years and the teacher has very gradually increased my range through warm up exercises. I have been working through various studies and I have never had a note in a new study which was too high for me to play because he has made sure my range was large enough before the higher notes started to appear in the studies. For example in warm up exercises I am up to a top B flat but studies at the moment are only going up to G. I looked a bit further on in the book and I have 3 more studies to do before A appears.
He has done a lot of work with me on airflow and embouchure so that I know what I should be doing in order to get the higher notes rather than blowing down the horn and hoping for the best. He was also very strict from the first lesson about too much pressure as he said he didn't want me later on having to rely on crazy amounts of pressure to get the notes above top F.
In the last few weeks we have started extending the range downwards so I can expect in the next couple of months to get studies which head down into the depths.
I love my lessons and have learnt so much in two years. I have yet to receive a single "piece" from him - only studies! He knows that I play pieces elsewhere and doesn't mind but he said he would much rather work on technique in the lessons and when he thinks the technique is good enough he will go on to some of the advanced horn repertoire. He said he is only using this method for me because he thinks it makes the most sense for me and said he teaches young beginners and adults with no other musical experience completely differently.
He also said he really enjoys teaching me because he can really work on technique as he does not need to teach rhythm or explain any theory and I don't have problems with intonation or hitting the right note on the horn. (I have other problems though - with breathing and tonguing and so on!)
I think your trumpet teacher should not be assuming you are a much better player than you are because you know your theory and play piano. He should be able to hear that there is a problem and assign appropriate exercises to deal with it.
Perhaps you could explain that you would like to be able to play the top A reliably and ask for some technical exercises to help you to reach that goal and also make clear that you know it can't happen overnight and are prepared to put the work in. Then see if he comes up with some sensible suggestions for you.
What sort of repertoire are you working on? How long have you been playing?