I've marched for a few years and never had a problem, but recently I decided to correct my technique and now have the mouthpiece exert very little pressure on my lips but as you can imagine, when marching when my feet hit the ground it skews the mouthpiece off my lips slightly and awful sounds come out. It isnt too bad on good roads, but what we call roads here, you may call mountain passes over on the mainland! We were practicing last night on a footall pitch and I certainly didnt do myself any justice! Especially on Sop!!! Are there any tips and tricks to playing effectively while marching. Ta!