Does anyone have Allen Vizzuti's book called High Notes, and has it improved your range at all? I've been doing lip slurs, scales two octaves, playing low, and just plain playing high daily, but it hasn't done too much. This leads to another question, My high C is pretty strong, and my D is fairly strong, it can be heard but it isn't ear piercing. But I can't play any higher than that. Maybe a D# but I can't play an E. Is this a sign of too much pressure?