@Dale-Proctor
Thanks Dale. I’ll give that a try.

@Vulgano-Brother I am not sure what you mean by a "rounded crook". Can you elaborate?

@ROWUK Thanks ROWUK. I've started the long tones, being very conscious of relaxing and releasing the air with as little pressure as possible. I fortunately have no performance commitments and so have the opportunity to be intentional about building new habits. While my initial question was about the intonation of a particular note on one of my horns, your comments have highlighted an issue with poor tonal resonance in the high G to high D range, among other things. It's pretty clear to me that the arm pressure and intense lip compression has been working against me. I am looking forward to working toward "easier" playing and I have already had some glimpses of the eventual outcome.

@ROWUK Too much pressure is surely part of my problem. I’ve made progress in posture, inhale and “exhaling”. I find that I must change my lip position and trumpet position to generate a note. Is that appropriate?

@JWM Thanks Richard III. That makes sense. I’ll make that part of my practice routine until it becomes “natural.”

@ROWUK
ROWUK, thanks for the response. I think it is likely I’m the problem. I’ll keep working on it. Any recommendations are appreciated.

@Dale-Proctor
Thanks Dale. I’ll give that a try.

I have trouble securely landing on high G# with my 1970 Bach 43. Same issue whether the interval is narrow or wide.
How can I determine whether this is me or the horn?