Hi Greg/all, I am a comeback player and have been gradually making my way through the course since October 2020. Things have been going well but I am currently on the Andante Status stage and seem to be running into problems. I have been persevering with harmonic slurs and aperture corners which until recently seemed to be going OK, but I am now noticing that more of my bottom lip is slipping into the mouthpiece when I go for slightly higher notes, resulting in early stages of ‘lip clamping’ syndrome! I am really trying to concentrate on maintaining the horizontal adjustment of aperture corners (aah-ooh), but I keep running into this issue. From a physical perspective my upper jaw protrudes very slightly over my lower jaw (like many people and nothing major) and I was wondering if this something to do with it? Is it necessary for me to consciously extend my lower jaw to compensate and help maintain the mouthpiece in the same position, or do I just need to concentrate more on my a/corners? Thanks.