Hello, I have a problem where when i get to the high Bb and start going higher i start to strain and close my throat. I don't do this in any other register.This is a problem that I have been having off and on lately and it usually goes away by itself. But I would like to know if there are any exercises that I could do to help me open up my throat in the upper register. my teacher had me doing breath attacks starting on high notes so that i could get the feel of the open throat in that register and he showed me some other exercises so that I would know how the open throat feeling is suppose to feel like, but now i can't seem to get it. What can i do? Also my second question has to do with slurring large intervals like 8va's. Whenever i hear my teacher (mr. rene hernandez) his lip slurs are so smooth and I want to get mine to sound like his. he suggested that I should practice slurring minor 3rds . Is their anything else that i can do? I've heard that over practicing slurs can hurt your sound. Also today when i lip slurred it sounded kind of smooth for a little bit but then i went back to sounding like crap. I will address some of these problems to my teacher on my next lesson but I just want to read someone else's thoughts. thanks for any help..