the muscles of the larynx, for then both vocal cords are drawn together and made tense as in phonation.  It is therefore not surprising if removal or destruction of this portion of the brain on one side does not produce paralysis of the muscles of phonation, which, always bilaterally associated in their actions, are represented as a bilateral group in both halves of the brain.  These centres may be regarded as a part of the physiological mechanism, but the brain acts as a whole in the psychic mechanism of speech and song.  From these facts it appears that there is:  (1) An automatic mechanism for respiration and elemental phonation (the cry) in the medulla oblongata which can act independently of the higher centres in the brain and even without them (vide p. 18). (2) A cerebral conscious voluntary mechanism which controls phonation either alone or associated with articulation.  The opening of the glottis by contraction of the abductor (posterior ring-pyramid muscles) is especially associated with descent of the diaphragm in inspiration in ordinary breathing; whereas the voluntary breathing in singing is associated with contraction of the adductor and tensor muscles of the vocal cords.

A perfect psychic mechanism is as necessary as the physiological mechanism for the production of perfect vocalisation, especially for dramatic singing.  A person, on the one hand, may be endowed with a grand vocal organ, but be a failure as a singer on account of incorrect intonation, of uncertain rhythm or imperfect diction; on the other hand, a person only endowed with a comparatively poor vocal instrument, but knowing how to use it to the best advantage, is able to charm his audience; incapable of vigorous sound production, he makes up for lack of power by correct phrasing and emotional expression.  We see then that the combination of a perfect physiological and psychological mechanism is essential for successful dramatic singing, the chief attributes of which are:  (1) Control of the breath, adequate volume, sustaining power, equality in the force of expulsion of air to avoid an unpleasant vibrato, and capability of producing and sustaining loud or soft tones throughout the register. (2) Compass or range of voice of not less than two octaves with adequate control by mental perception of the sounds of the necessary variation in tension of the laryngeal muscles for correct intonation. (3) Rich quality or timbre, due partly to the construction of the resonator, but in great measure to its proper use under the control of the will.  Something is lacking in a performance, however perfect the vocalisation as regards intonation and quality, if it fails to arouse enthusiasm or to stir up the feelings of an audience by the expression of passion or sentiment through the mentality of the singer.