A certain amount of work or energy must be expended to produce any given tone. This varies to an enormous degree, according to the state of technical proficiency of the singer. Under ideal conditions the effort which must be expended is determined by the amount of work necessary to tense the muscles are, and should be, used in phonation. In practice other muscles come into tension. These muscles come under two headings:

1. The interfering muscles which co-ordinate – incorrectly – with phonation. “Pre-tension” comes under this heading.
2. Muscles which come into tension but which do not co-ordinate with phonation.

Both these groups of muscles should, of course, be relaxed and, during the process of training the voice, the tension on them should always be lessening. In bad cases, however, the tension on these two groups of muscles is extremely high, under which circumstances the work which must be done in order to sing is enormously augmented.

We could state this in the form of an equation.

Thus, if:

W=Total muscular tension (i.e., total work done by the singer when he produces a given tone)

X = Tension on muscles which should be used in phonation

Y = Tension on interfering muscles

Z = Tension on muscles not co-ordinated with phonation

Then: W = X + 2Y + Z

This means that the “work done” (muscular tension) required in order to sing a given tone is equal to the “work done” in order to tense the muscles which should be used in phonation, plus the “work done” in order to overcome this tension, plus the “work done” on muscles which become tense but do not co-ordinate with phonation.

In view of the fact that both Y and Z can be of any magnitude, the reader will readily understand why it is that the singer who has been trained incorrectly, or who used the voice badly, is forced to make so distressingly great an effort. In extreme cases it would be conceivable for the tensions Y and Z to become so great that it would be impossible for the singer to produce tone at all. The tension Z does not count in producing the tone and the tension Y must be overcome by an equal tension if the singer is to produce sound at all. Thus, he can do an enormous amount of work, i.e., make a tremendous effort, and actually be doing no work at all, as applied to the production of tone.

Apart from other considerations, then, it will be seen how important a part of the teacher’s work lies in the elimination of interfering and incorrect tension when the pupil is singing. When he has succeeded in reducing both Y and Z to minimum proportions, the work done by the pupil in order to produce tone, is by no means great; in fact he is then able to sing with consummate ease.

Stanley, Douglas. Your voice: Applied science of vocal art. Pitman Publishing Corporation, 1957.