I stumbled across Charlie’s videos first (before I found Greg’s) and for some reason, something clicked for me–I think the “straight line approach” video just worked inexplicably for me–I started hitting notes somewhat effortlessly that I never could before. I like Charlie’s other videos too, but eventually I wanted more and Greg’s videos and course, for me, fill in the gaps and actually helped open up my mind and connect for me how it seems now that all the approaches / methods I have ever read / been exposed to seem to actually say the same thing, rather than contradict each other as it first seemed. Charlie’s videos got me to squeaking out A above the staff to high C, but Greg’s video’s and course turned those notes into actual notes and got me up to high F above high C. The Maggio monkey has been helpful too–I bought the Maggio book but haven’t even done the exercises, but looking at the picture and skimming through the book / thinking about is as I play helps me remember the aperture corners moving in as I ascend.