I've been struggling with the third overtone for a little while. I was taught that it should mainly be achieved with throat position, tongue position, and air, as opposed to embouchure changes. When I mess around with my throat position to try to get up there, pretty often my gag reflex is activated and so it is hard for me to voice it. I think my normal throat position is fairly open. I can reach the third overtone if I apply a lot of force with my abdominal muscles, basically overblowing it, but at that point I can't really play it quietly and controlled.
Does anyone else have any experience or advice with the gagging problem?
Does anyone else have any experience or advice with the gagging problem?