So I've started practicing with a mirror and I noticed that once I start to get above a high F (Bass Clef) I start to get a smiling embouchure and I think it effects my endurance. Additionally I noticed that my tone thins out very quickly.
My question is, what exercises can I do to work my way out of the smiling embouchure and what can I do to decrease the amount of pressure I put on the mouthpiece when I start playing at the top of my range? How do I open up the sound?
I have an honor band to go to in late November and one of the songs has a high B flat two or three times. I can play the note, but it's not pretty, and I can't always hit it in that context. However, I do think a month is a reasonable amount of time to get more comfortable with it.
All advice is appreciated
-TJ