This is a little off topic. I have watched a bunch of various musicians breath while they are playing. With every one of them you can see the rib cage expand, causing the chest to rise. Just as they start to play the chest drops slightly and their abs come in. I believe this energizes the air stream. I've been told by a lot of teachers never to drop the chest. But it happens. I guess they mean don't play with a collapsed chest. Anyway, I view this as my own little version of wedge breathing. I used it last school year with my middle school kids. Showed them the rib cage expanding and the abs coming out upon inspiration, and then the abs going in and the chest dropping down just as they start to play. Last year my kids had the best sound I've ever been able to achieve with middle school kids. Big, focused, robust. Judges commented on the "mature" sound.