To Practise a Song
The student, when practising, should stand firmly (on both feet) in an upright, easy position, the head erect, the chest well expanded, the shoulders kept downward; he should open the throat as wide as possible, but the mouth only moderately, drawing the lips rather tight, so as just to show the upper row of teeth, as in smiling, in order that the sound striking a hard surface (says Signor Lamperti), may vibrate with greater intensity, and give a ring and brilliancy to the voice.
It is a great mistake to open the mouth too much—it causes a thick, unpleasant sonority, and renders rapid and distinct articulation impossible. The tongue should remain at full length, so as to leave the largest space in the mouth.
The student would do well to practice before a looking-glass, or hold a small mirror in his hand, to see if the aperture of the throat and the uvula are visible.
M. Lutgen.
—The Etude, March 1, 1894, page 52.