When the voice is working properly, the majority of the functional response is inside. The idea that you can make a good deal of sound without widely opening the mouth or dropping the jaw a lot is in many classical approaches and is aligned with the behavior of a ventriloquist. If the work travels into the external muscles the larynx will have a harder time doing its job freely and the sound will suffer accordingly. Everything from the strap muscles on the side of the neck, which are secondary laryngeal stabilizers, to the muscles in the base of the tongue, the jaw, or the back of the neck (a typical place for tension) should be involved in vocal production as little as possible.
It is paradoxical that you can have tension and freedom at the same time but this is true of all muscular activity that requires strength and flexbility in balance. In order to move quickly the muscular movements must be small. If you make large lumbering movements it is nearly impossible to go quickly and lightly, no matter what the task. Flexibility exercises for the muscles of the face, mouth/lips and tongue help counter exercises in which the mouth remains open for long periods of time, sustaining open vowels at moderate to loud volumes.
Flexbility in the back or base of the tongue is another matter altogether, however, and is much harder to access, because we don’t move those muscles deliberately. We do not much need them to do more than the minimum necessary for articulating normal colloquial speech. The larynx is suspended in the front from the muscles at the base of the tongue, so its flexibility is a key ingredient in rapidly moving phrases. Rapid melismatic phrases ask a great deal more of the tongue and it takes great patience to develop pitch accuracy and speed in a voice that is also easily full and loud because these movements in the tongue, that are not automatic, must be deliberately cultivated. Callas wrote about how much she worked on articulatory exercises with her teacher, Elvira de Hildago, who was a coloratura. Those drills served Callas well in her career, particularly in the Bel Canto repertoire.
In a beginning student with no previous singing training a great deal of time has to be spent on getting the person to allow the jaw to drop and the mouth to remain comfortably open (about the width of a thumb) without forcefully pulling the jaw down and holding it there rigidly. The muscles of the face, inside and out, have to lengthen through stretching, over time. As this work takes hold, if the student is also encouraged to sing with an enlivened facial expression, the muscles of the soft palate, which stretch across the back of the mouth, will also respond, lifting and stretching. The inside of a trained singer’s mouth looks very different than that of someone who has had little training. The musculature becomes defined rather than gelatinous and can be quite taut when activated. The muscles of the side walls of the throat that constrict it in order to swallow should be, as much as possible, at rest while singing. The problem, of course, is that thinking about this won’t help much, as the swallowing muscles operate largely below the level of conscious awareness unless we swallow on purpose. Most people who “swallow their sound” don’t do so deliberately and often have no idea that this behavior even exists.
As a vocalist gains more skill, it is possible to close the mouth (bring the jaw up) to a smaller opening while having the back of the throat (velopharyngeal port) remain lifted and open. The closing of the jaw releases it, releases the back of the tongue and allows the facial muscles more ease in changing position. Asking a beginning student to do this, however, is usually counter productive.
This discussion leads us next to habituation versus conditioned response. Human beings can become accustomed to almost anything, even things that are very unpleasant and uncomfortable. Some people even find things that are painful to be rewarding. We call those people masochists. Behaviors we become accustomed to become habits, things we do without paying attention. Many people sing quite decently around chronic tension in any and all muscles that effect vocal output but that doesn’t mean that their vocal production is optimal. The best vocal production occurs when the larynx is operating efficiently, the rest of the muscles are free to move and adjust, the airflow is controlled by a balance of activity in the ribs and abdominal muscles and the lips, tongue and jaw are free to form vowels and consonants.
The training process is supposed to isolate habits that are useful from ones that are not. It is supposed to counter unproductive behaviors by developing opposite ones that are corrective or developmental. It is supposed to strengthen good habits without having them become predominant. Working from a functional place, the teacher has to know good function from bad. The teacher has to understand how to work one group of muscles until it is free from another and when to stop going in one direction to go in the opposite direction. The teacher has to understand what is manipulation and what is exaggerated behavior done for exercise purposes only. The teacher has to know. The T E A C H E R.