1st off sorry if I misspelled embouchure The title might be a little misleading since its not really an embouchure problem but I have no other way to explain it. Before I start playing my lips feel soft, pliable, and loose like normal and I when in that state I play great but after I stop playing (not during) my lips feel firm and tight almost muscular in a way if that makes sense. When I start playing again later in the day with this firm feeling I end up playing slightly (pretty insignificantly) worse with slightly less range, flexibility, and a weaker tone and when I stop playing after that the firm feeling is even more so and I play even worse the next time I play. I play in 3 school ensembles: Jazz before school, band class during school, and marching after school, all of these spaced about 3 hours apart from each other so this becomes a problem by the end of the day. If I go a significant time without playing (like 5 hours or so) my lips return to their soft, pliable state and I play great again. Can anyone explain why this happens and how to avoid this and keep my chops feeling nice and loose all day.