@voicewisdom Excellent observation! But are these two the only muscles that are working too much? Could you perhaps list ALL the muscles which the singer uses too much in order to sing? And could you also share your assessment of the relative amount of the sum total of additional and unnecessary muscular effort that this student creates before and after the hands-on part of her lesson?
One of the most significant features of this demo is that the singer jerks her chin up and forward on the inhalation. The constrictor muscles pull on the larynx, impairing phonation (ease of making the note), and resonance, as well as tightening the masseter (biting muscle). The teacher seems not to notice this at all. The damage is done before the singer even makes a sound!
Don Weed is an excellent Interactive Method teacher. I have tried traditional and ITM and would never go back to the former. ITM is so much more accessible.