What I would like to know is why those simple exercises work so well? I've seen the same thing you have, Ed, with those slow lip slurs. I'm wondering if anybody knows why (or how) they work?
Yep, it's concert season down here as well. It's the flute and tenor sax sections in my band that are driving the rest of us crazy. The flutes can't play in tune and the saxes can't see the key signatures!
As for encouraging words----here's a thought: try to find a church to practice in. I've seen quite a few churches where the acoustics are really good and even little mistakes get noticed. That will keep the practice from getting sloppy and you'll probably love the sound of the music soaring through the open spaces. I have a little church with acoustics like that and I love to play over there.
Bill