A run or any other figure must never sound thus:
but must be nasally modified above, and tied; and because the breath must flow out unceasingly in a powerful stream from the vocal cords, an h can only be put in beneath, which makes us sure of this powerful streaming out of the breath, and helps only the branch stream of breath into the cavities of the head. Often singers hold the breath, concentrated on the nasal form, firmly on the lowest tone of a figure, and, without interrupting this nasal form, or the head tones, that is, the breath vibrating in the head cavities, finish the figure alone. When this happens the muscular contractions of the throat, tongue, and palate are very strong.
The turn, too, based on the consistent connection of the tonal figure with the nasal quality,—which is obtained by pronouncing the oo toward the nose,—and firmly held there, permits no interruption for an instant to the vowel sound.
How often have I heard the ha-ha-ha-haa, etc.,—a wretched tumbling down of different tones, instead of a smooth decoration of the cantilena. Singers generally disregard it, because no one can do it any more, and yet even to-day it is of the greatest importance. (See Tristan und Isolde.)