The art of music, Vol. 05 (of 14)

by Unknown

Each of these organs performs a different function in the production of useful and beautiful sounds. It is the generally accepted view among vocal scientists that each portion of the vocal mechanism has one and only one correct mode of operation. Many forms of incorrect action are also possible; indeed, the untrained voice is believed to be liable in almost every case to faulty operation in some respect. Scientific investigation of the voice has for its purpose the determining of the correct muscular actions of the various parts of the vocal mechanism, and the formulation of exercises whereby the student is enabled to acquire command of these actions.

Modern methods of voice culture embody the results of scientific study of the vocal mechanism. It must be observed that not all investigators are agreed upon what constitutes the correct vocal action. Several conflicting theories have been urged concerning the proper movements of the breathing and laryngeal muscles and the operations of the resonating cavities. An exhaustive treatment of these various theories is, however, not called for here. Some of them have been discarded, others have but few followers. The majority of authorities are in fair agreement concerning the theoretical basis of voice culture. In the present chapter only the theoretical aspect of the subject will be considered; the third chapter will be devoted to the practical methods which embody the doctrines of vocal science.

Two opposed sets of muscles are concerned in the operations of breathing, those which, respectively, fill and empty the lungs. The action of inspiration consists of an expansion of the chest cavity, which by increasing its cubical capacity draws in air from the outside to fill what would otherwise be a vacuum. The chest cavity is conical in shape, its base being formed by the diaphragm, and its sides and apex by the ribs, the breast-bone, and the intercostal muscles.

Broadly speaking, there are two distinct forms of muscular action by which the chest cavity can be expanded in inspiration: one is the sinking of the base of the chest cavity, the other the broadening of the chest by raising the ribs. Either of these can with some little practice be performed independently of the other.

The sinking of the base of the cavity is accomplished by the contraction of the diaphragm. This muscle is roughly circular in outline. In its relaxed state it rises to a dome in the middle and might be compared in shape to an inverted bowl. As it contracts the diaphragm flattens out and increases the length of the vertical axis of the chest cavity. In its descent it pushes the viscera downward and forces the abdomen to protrude slightly. This manner of breathing is commonly called abdominal, although the muscles of the abdomen are not directly concerned in the filling of the lungs.

The expansion of the chest cavity may be accomplished by the raising of the ribs. Owing to their curved shape and sloping position, a slight elevation of the ribs causes them to rotate outward from the central axis of the chest cavity. This increases the horizontal diameter of the cavity in every direction—forward, backward, and sidewise.

In the judgment of the most competent investigators the best form of breathing combines the two muscular actions just described. At the start of the inspiration the diaphragm descends, but the protruding of the abdomen is checked almost instantly by a contraction of the abdominal muscles. The inspiration is then completed by the lateral expansion of the chest. In this manner the lungs are filled to their greatest capacity in the least possible time. Another great advantage of this type of breathing is that it imparts a peculiarly erect and graceful carriage, a matter of much importance to the singer and public speaker.

In the action of expiration following the taking of a full breath in the manner just described two sets of muscles are involved. These are: first, the abdominal muscles, which push the diaphragm back to its original position; second, the muscles which lower the ribs (the internal intercostals and some of the external abdominal muscles). The actions of both these sets of muscles can easily be observed. When correctly performed the two actions are simultaneous, the whole chest cavity being gradually and uniformly contracted.

A highly important feature of correct breathing, in the opinion of most authorities, is the control of the expiration. In the first place, all the expired air must be converted into tone and none of it allowed to escape unused. Further, the vocal cords must not be exposed to the full force of a powerful expiratory blast, as they are too small and weak to withstand this pressure without strain and injury. The air must be fed to the vocal cords in just sufficient quantity to serve the purposes of tone production.

It is generally held that this economy of breath can be secured, without strain on the vocal cords, only by opposing the action of the inspiratory muscles to the action of the muscles of expiration. Instead of allowing the inspiratory muscles to relax completely at the beginning of the expiration these muscles are to be held on tension throughout the expiration. By this means both the force and the speed of the expiration can be regulated at will; no undue pressure is exerted on the vocal cords, and the tone is prolonged steadily and evenly so long as the expiration lasts.