§ 29. In the same Lessons, let him teach the Art to put forth the Voice, which consists in letting it swell by Degrees from the softest Piano to the loudest Forte, and from thence with the same Art return from the Forte to the Piano. A beautiful Messa di Voce,[14] from a Singer that uses it sparingly, and only on the open Vowels, can never fail of having an exquisite Effect. Very few of the present Singers find it to their Taste, either from the Instability of their Voice, or in order to avoid all Manner of Resemblance of the odious Ancients. It is, however, a manifest Injury they do to the Nightingale, who was the Origin of it, and the only thing which the Voice can well imitate. But perhaps they have found some other of the feathered Kind worthy their Imitation, that sings quite after the New Mode.
§ 30. Let the Master never be tired in making the Scholar Sol-Fa, as long as he finds it necessary; for if he should let him sing upon the Vowels too soon, he knows not how to instruct.
§ 31. Next, let him study on the three open Vowels, particularly on the first, but not always upon the same, as is practised now-a-days; in order, that from this frequent Exercise he may not confound one with the other, and that from hence he may the easier come to the use of the Words.
§ 32. The Scholar having now made some remarkable Progress, the Instructor may acquaint him with the first Embellishments of the Art, which are the Appoggiatura's[15] (to be spoke of next) and apply them to the Vowels.
§ 33. Let him learn the Manner to glide with the Vowels, and to drag the Voice gently from the high to the lower Notes, which, thro' Qualifications necessary for singing well, cannot possibly be learn'd from Sol-fa-ing only, and are overlooked by the Unskilful.
§ 34. But if he should let him sing the Words, and apply the Appoggiatura to the Vowels before he is perfect in Sol-fa-ing, he ruins the Scholar.
