After reading the thrilling thread on valve oil and the widespread disagreement on do's and don'ts, I thought I'd open up discussion on another practice. I had a teacher, at one point, advote the practice of "buzzing" with a mouthpiece, in order to extend practice time beyond when one can play a horn. For example sitting in front of television or while driving...etc. As I find myself increasingly strapped for time, I've started to do this while driving. While you can't actually practice, you can focus a "pitch," work on breathing, build some endurance (just from contact time on the chops) work on flexibility and work on tonguing. The thing I wonder about is what peoples opinions are on the possible damage I could do, since I'm not actually playing notes/hearing the result of my effort as I "practice." Do you think it's good for the kinds of things I mentioned (obviously not a substitute for practice, but an addition to it)? or Do you think I could be doing more harm than good. I haven't been doing it long enough to notice any effects either way yet, just wondering about any of your thoughts.