The pedagogic theories espoused by Cornelius Reid over the course of a seventy year teaching and writing career are based on the works of the early teachers of the eighteenth century.  The main focus of those masters was the vocal registers, the chest voice and the falsetto.  To this Reid has added the insights provided by physiological research as to how the vocal mechanism works.  In his research he discovered that the most efficient way to train the vocal mechanism was not by the institution of overt control systems, but by working indirectly.  Since the muscles that bring the vocal folds into tension are involuntary, the entire mechanism must be treated as such.

Considered from this perspective, Reid’s training philosophy is founded on what amounts to an ecological principle, where the vocal mechanism is regulated and controlled by changes in the environmental conditions to which it is being exposed.

How is the correct environment chosen?  By listening to the tonal product.   Mechanically, the singing voice naturally divides into two distinguishably different qualities, or registers, known as the chest voice and the falsetto.  The purpose of technical training is to develop and blend these two qualities so that the voice becomes a seamless entity.  By working registrationally it is possible to equate what is heard with the probable balance of tension operative within the laryngeal musculature.  On the basis of this analysis, a vocal exercise is created that is the most beneficial environment capable of serving the student’s growth needs.

How does this operative principle manifest itself?  It becomes apparent by observing a series of equivalencies.  For example: The vocal folds adjust their length, mass and tension to accommodate numerous combinations of the three basic tonal elements, pitch, intensity and vowel.  Change the pitch and/or intensity and the vocal folds will adjust their physical dimensions accordingly.  As a result, the antagonistic contractions of the muscle systems will correspondingly shift their ratio of tension to accommodate those changes.  Change the vowel, and both the configuration of the vocal tract and the conformation of the vocal folds will also change, each change having a direct bearing on quality.

The equivalencies noted above can be worked into an exercise construct that invokes the above-mentioned principle. Thus, a specifically designed exercise will predictably result in a special type of vocal fold conformation whose dimensions will, in turn, be determined by the proportional amounts of tension assumed by the tensors of the vocal folds.  It is within these relationships that the operative principle by which the vocal registers are governed is to be found.