@johnelwood I may have misled regarding using “burst of lung and throat air.” This only refers to my efforts at stab notes. The question in my post is focused on Greg’s demonstrations at 8:08 to 9:20 in the Compression Depression video linked above. Otherwise, I think I am good with passive air above the staff, within my current range constraints. I am working on Ruby Singing C at Ab and A and can get thru #1, 3 and 8 reliably. Inconsistent when I try to add volume in the other exercises. I can feel myself resorting to mp pressure too often. Need to work on this. BTW, I think your commments are on target regarding optimizing my shape. I need to continue to work on this too. I have read a good number of your posts and am appreciating your insights and attention to detail. Thanks.