Reid, Cornelius L. Vocal Mechanics and the Cultivation of Listening Skills.
With the two register theory a verifiable fact, procedures concerned with the development and integration of these basic qualities become issues of extraordinary pedagogic importance. Unquestionably, if a valid connection is to be made between the quality of the tonal product and the physical and acoustic activities associated with its appearance, the tonal product must be critically observed and studied at its most primitive mechanical level.
Given the natural tendency of the voice to divide into two parts, the chest voice and the falsetto, the immediate area of pedagogic interest is to link these special qualities with those muscle systems whose activity accounts for the variables in their pitch ranges and quality characteristics. At the same time, these qualities and their corresponding muscular equivalents must be associated with the special combinations of pitch, intensity and vowel, presented in the form of a vocal exercise, whose energies are responsible for their appearance.
As the foregoing relationships apply to functional listening, when the bulk of the vocal folds (vocalis) increases in the lower pitch range of the voice with minimal cricothyroid participation, a rather crude and masculine tone quality will appear, whose special properties are commonly recognized as a chest voice. The emergence of this tonal characteristic is facilitated when an ‘AH’ vowel is sung at a high level of intensity concentrated within a pitch range extending from E above middle C to include pitches extending downward.
On the upper side of the division, or ‘break’ in the voice, the complexity of falsetto mechanics can be traced to the degree to which parts of the arytenoid system oppose the pitch regulatory function of the cricothyroids. Opposition provided by the arytenoid system can occur in several ways. For example, an isolated, totally ‘false’ tonal quality will emerge when the vocal folds remain fully opened, in which case the optimally engaged posterior cricoarytenoids would merely brace against the active contraction of the cricothyroids. As a consequence of this arrangement, the quality characteristics of the tonal product will be an extremely breathy, short ranged and harmonically impoverished pure falsetto, located in a pitch range extending from A below middle C to an octave and a third above.
The vowel directly associated with the quality characteristics of a pure falsetto is an exceedingly breathy ‘OO’, having a rather toneless tone quality, sung within the above mentioned pitch range. Without exception, this type of falsetto stands aloof from all aesthetically satisfying tonal qualities, since it possesses no vibrato and is unable to function cooperatively with those elements of the arytenoid system whose tension both thickens and approximates the vocal folds and is qualitatively associated with a chest voice.
Numerous and different types of ‘false’ tonal qualities surface when increased arytenoid tension causes a series of gradual shifts to take place, with vocalis tension especially becoming more active as the tonal quality attains greater legitimacy. Each stage of this balancing process alters the degrees of falseness variously described as weak, dull, acute and ringing, effeminate and/or considered to be semi-legitimate.
The presence of these qualities, however, is not necessarily indicative of a legitimate, or even an aesthetically acceptable and functionally efficient tone quality. Perhaps a more satisfactory way to describe tonal legitimacy is to associate its special physiological properties with the degree to which vocalis activity thickens the vocal folds as it opposes cricothyroid tension.
In addition to this arrangement, legitimate tone qualities are those that find the vocal folds fully approximated, coupled with an appropriate length and thickness sufficient to ensure a reasonable resonation of the fundamental frequency. It is important to note, however, that a legitimate quality is merely one that is not considered to be ‘false’, it is not necessarily healthy, nor free of muscular imbalances and varying degrees of throat constriction.