It has been a real pleasure listening to many horn players over the last few week who I don’t get a chance to hear on a regular basis! Such a wide variety of styles, sounds and techniques has been really fascinating. One thing that happens a lot is lack of attention to the pitch of the note at its end, both when the note connects to another and when it is the last note of the phrase. Even if the basic sound is efficient and good, when the pitch changes at the note’s end, especially when it happens on every note in a sequence of notes, it can ruin anything good that is happening in the phrase.
Watch for 2 things (these are usually the culprits):
As the mind’s attention goes to the “next thing” (note), the foundation of air flow and pressure wanes, resulting in a fall in pitch (just like a balloon that loses air).
Watch if you can the movement of the tongue at the end of the note. Sometimes this is such a habit that it is impossible to feel. Any extraneous movement of the tongue in unconscious preparation for another event (note) can alter the pitch. Wait until the last possible instant to prepare the tongue for the next note, focusing on the solidity of the air flow as a means of solidifying this attention.