OK, so I was practicing the other day and while playing my upper long tones I notice my notes from E above middle C to F# above middle C sound stuffy if I could call it anything. It doesn't sound forced and but it sounds as though something might be lodged in the horn. I already cleaned out in an attempt to fix the problem. Presuming that the problem was something blocking the air passages I scrubbed them thoroughly. Well, the horn was in pretty good shape as far as cleaning and nothing was lodged in the valve casings nor the any or the pipes. Everyhting checks out. Clean as a whistle. So, I got back to playing the long-tone series again. Sounds full until I get to the E and it sounds and now FEELS like something has been placed in the pipes somewhere. Check out the horn again. Still nothing. So, now I assume it is my playing. I believe my embouchure may be the problem. I believe I may be closing the appeture (sp?) a little to far a little prematurely in preparation for the higher partial. That is the only trouble spot I have noticed in my practicing lately so maybe that's a good thing. Please help me out if you can.