Mujitsu and Tairaku's Shakuhachi BBQ

I would like to know something on how to exercise and how the throat should stay while we played.

On the first instructional video at Mejiro (http://www.mejiro-japan.com) Keisute Zenzyoji says:

"it's very important to expand the area at the base of your throat. It increases volume and it's good to steady your breathing."   OK

To exercice:

"widen your throat as if you are about to yawn..."   then he propouses: "If you are male, touch the side of your throat.   You will feel your Adam's apple go down."

I can place the throat in the suggested shape but I think it is unmaked as I am going playing... How to exercite the opening of the throat? How should it stay?

Peace