I was thinking about you / this thread this morning as I was doing some flexibility exercises.
FWIW, it doesnt take much at all for me to flex from C to E on the staff or even higher when I am playing correctly, things feel right. In fact, I sometimes skip a harmonic accidentally and go too high.
It seems to be all about engaging those corners. When that is going good, its amazingly easy sometimes–to the point of over shooting the target.
Before WindWorks, I used to use my air to kick up from one note to the next a lot when doing harmonic slurs. I believe that was due to the inefficiency of my embouchure and a misunderstanding of how the instrument worked.
One of the key benefits for me of WindWorks has been how Greg cuts apart the concept of Shape defining Pitch and Air defining volume or duration.
I focused for many months almost all my time on playing with passive air (releasing) with little or no abdominal support whatsoever. I really focused on the aperture corners and experimented with different intensities.
In my opinion, the single most important exercise ( if there is one) in understanding WindWorks is a harmonic slur with passive (released, not blown) air, as it helps us focus in on how effective / efficient the Shape (of the aperture) we are forming with our embouchure is.
I think thats why Greg has those progress charts, to help us realize how things are going–at what point are we getting tight / cutting off, getting less efficient, etc.
You mentioned in your first post above something about more compression going from C to E. That is the harmonic I focused a lot on when I was getting the feel of the corners. I think thats a good one to focus on as the interval is small and its getting to the top of the staff. Low C to G on the staff is a big interval and kind of like youre flipping from low to middle registers, whereas C to E is closer, etc.
The results exercises are important too, as is playing music–which is ultimately what we’re after and which should be our ultimate judge/guide.
When I catch myself doing too much technical studies amd not enough music, I catch myself losing my way and manipulating and not using a more natural form (embouchure). It seems to me that the most natural and relatively relaxed (except the corners) I play, the better I sound and feel and the bettet my range and flexibility.
Its when I make it harder than it really is out of fear/doubt or over thinking it that things go south.
Its kind of a paradox that the only way to have control (relatively) is to let go/relax.
But I feel like it makes sense now. It is starting to seem consistent, logical, etc. And less of a mystery.