TromboneChat

hi, i've been trying to really imrpove my high range since last year, and although i can "hit a G4 and Ab4 pretty consistenly, suddenly my range collapses at A4 and above.
i'm having a really hard time trying to hit that high A aceptable for playing, every time i attack that note my tone becomes very fuzzy and i feel that my lips are vibrating roughly, making sort of a flutter tone.
Soft playing that A is also nearly imposible for me, and everytime i need to play that note i make a small glissando to be able to hit it, it's very frustating since i can't make a good Bbmaj7 arpeggio without sounding bad.

Also, my worst note possible is the High Eb, i can sometimes hit that high F, but after months of trying, the sound just dosen't come off for the High Eb in 3rd, i mostly hit the partial above it.

i'm doing the usual, lots of lip slurs skipping the 7th partial, two octave scales (although my tone gets bad after that high A). i 've been trying to do this excercise in which you slur fast from a low Bb to a High Bb in 1st position using only air, without success since i cant't even make it to a Mid Bb in triplet 8th notes doing slurs at 110bpm.

My Teacher says, "it's just about air" "you have to put more air into the horn" "tounge, has nothing to do with hig hrange, making vowels may or may not be helpful"

Any suggestions are welcomed

I most often play that high Eb in a #2nd. See if that slots better for you.

And I play E in a #4th, and F in a #3rd.

I've experienced somewhat of a similar thing recently. Used to really struggle above the F# (2 lines on top of bass clef), above that it all sounded very airy, very strained and it certainly didn't feel good to play. The way I've worked on it with my teacher is through mouthpiece buzzing in a spyrometer, with that my teacher helped me find the correct embouchure for those notes with which I struggled. Specificcally for me was a matter of strenghtening the corners in order to keep a nice amount of chops inside the mouthpiece (basically not smiling while playing high) whilst maintaing an open oral cavity.
For the "it's just about air" maybe try and find a way to visualize the speed of the air: an image that makes you blow faster (ex. throwing a dart or drilling a hole --> Adam Rapa talks about this concepts try and find some of his videos on youtube)