No problem, Bo, just wanted to make sure what I understood was correct.

Doesn’t sound like you’re too far off from where I’m at. I don’t believe lowering the jaw to open up the aperture, if necessary, is a bad thing–it surprises me still how open one can play up there.

Lately, I’ve been working a bit / experimenting a bit trying to grow my range above High C and it feels like I’m kind of opening up my aperture a bit to get up to the E and above.

One thing that’s been helping me a bit lately, despite it being a chromatic scale, is Clarke’s First Study (Technical Studies)–# 25 starts on the F# at the top of the staff and ascends to High C. The key is playing it PP as written. I do have a sensation of “leaning in” to the notes as I ascend, but I don’t kick the air or use my abdominals to get the High C, it feels more like I’m very gradually reducing the aperture and kind of supporting the aperture with the “aperture corners”.

Hope that helps FWIW. Is your granddaughter still playing, BTW? You shared previously that she was trying it out.