Hi Scott.
As someone who took Alexander Technique lessons weekly for over five years (and who has read a LOT of books about Alexander Technique in the process), I would caution you a little about thinking that the book you’ve referenced really has much to do with playing the trumpet per se. If you look up a list of other works by Ethan Kind, you’ll see that he has written a whole suite of ebooks about “Alexander Technique and [[insert activity here]]” which are largely cut and paste exercises. It’s absolutely true that Alexander’s insights can be applied in many different spheres, but the title of this book is rather misleading in the sense that it seems to imply the advice therein is specific to trumpet players.
One of Alexander’s strongest insights was that we often need to learn to inhibit a learned and deeply engrained motor pattern that we typically apply to a specific activity before we can find a more efficient and easier way of performing that activity. Alexander acknowledges that it is very difficult for us to learn to inhibit engrained inefficient patterns, which unfortunately always “feel right” to us, and to which we tend to revert precisely because they “feel right”. All this is spelled out pretty well in “The Use of the Self” which Greg holds up at the start of this video. This is by far the most accessible and easily understood of Alexander’s own four books (he was a pretty terrible writer, in the main). While there are some excellent books written about Alexander Technique, there’s really no substitute for having a couple of Alexander Technique lessons if you really want to experience what it’s like to inhibit a learned way of doing something (typically, in an Alexander Technique lesson, rising from a chair – but this is only an example) and how very weird it feels to be using one’s body in a novel, non-deeply-engrained way. It seems to be there are obvious and strong parallels between what Alexander taught and what Greg is teaching in this respect. “Knowing” this, though, is just a booby prize really. I “know” it myself, but that doesn’t mean I can “do” any of this very well (in fact I can’t). But the “knowing” is presumably a start…