The scale is the greatest test of voice production. No opera singer, no concert singer, who cannot sing a perfect scale can be said to be a technician or to have achieved results in her art. Whether the voice be soprano, mezzo or contralto, each note should be perfect of its kind, and the note of each register should partake sufficiently of the quality of the next register above or below it in order not to make the transition noticeable when the voice ascends or descends the scale. This blending of the registers is obtained by the intelligence of the singer in mixing the different tone qualities of the registers, using as aids the various formations of the lips, mouth and throat and the ever present apoggio without which no perfect scale can be sung.
[Facial Expression and Mirror Practice]
In studying a new rôle I am in the habit of practicing in front of a mirror in order to get an idea of the effect of a facial expression and to see that it does not take away from the correct position of the mouth.
The young singer should practice constantly in front of a mirror as soon as she begins to sing songs or to express emotions in her music, for the girl with the expressive face is likely to contort her mouth so that the correct emission of tones is impossible.
The dramatic artist depends largely for her expression on the changing lines of the mouth, chin and jaw, and in any lines spoken which denote command or will you will see the actor's jaw setting and becoming rigid with the rest of the facial mask.
Now, a singer can never allow the facial expression to alter the position of the jaw or mouth. Facial expression for the singer must concern itself chiefly with the eyes and forehead.
The mouth must remain the same, and the jaw must ever be relaxed, whether the song is one of deep intensity or a merry scale of laughter.
The mouth in singing should always smile lightly. This slight smile at once relaxes the lips, allowing them free play for the words which they and the tongue must form and also gives the singer a slight sensation of uplift necessary for singing.