This is a wonderful ordination of divine wisdom for the purposes of diftinguishing the fex, and of delight and inftruction in speaking and finging.

The tenor, confined to its natural limits, may be confidered as an octave below the treble, the contratenor an octave above the base, and the base an octave below the

tenor.

Let the mafter then in teaching, and the scholar, in learning to fol-fa and form the voice, carefully attend how to open the mouth, that the tones may come forth freely, without any interruption of the throat, tongue, teeth and lips, and how from the low to gain by degrees and in perfect union, resembling a peal of bells, the high notes-ftriking the lower firm, round and full di petto, and the higher di tefta, with proportionate softness and proper rotundity, to prevent screaming, fqualling, and hooting.

The higher tones, if not given by nature in a foprano and contralto, may be acquired very agreeably by art di tefta, from a management of the throat by narrowing

the wind-pipe, somewhat fimilar to the leffer pipes in an organ, and to the pinching of notes judiciously in a wind inftrument. Let the mafter fee that the voice, both di petto and di tefta, come forth neat and clear, neither paffing through the nofe from a fault of contracting the jaw, nor choaked in the throat by drawing back the tongue, which are two the moft infufferable tricks and defects in a fpeaker or finger.

The master and scholar should be of diligent attention to difcern where the full natural voice di petto terminates upwards, generally and best in a foprano about d; it rarely comes to g in alto without fcreaming, and in a contralto at g, a or b, scarcely higher without feigning; and from thence upwards help the learner to gain the notes di tefta or falfetto, fo united with those di petto, as they may not be distinguished, both in going up to the highest artificial notes, and in returning to the real below.

If the real and artificial tones do not perfectly unite or agree, the lower covering, like the greater bell, or a well formed organ and harpfichord, the next above through

through the whole peal, the voice will be of different founds, or as Tofi fays, of diverse registers, and confequently cannot be heard with delight.

Under this management a good natural voice of any kind will charm, and an indifferent voice may be made agreeable.

In preferving a unity of tone naturally and artificially, confifts the delight and excellency of a voice and instrument.

Height, Depth, and Measure of Sounds.

Having gone through with the doctrine and theory of mufical founds, fingle and in combination, we shall now proceed to other properties, their height, depth, and measure.

Sounds produced in speaking and finging are of three kinds, high and low, either in gradual fucceffion, or in distances, called intervals, and monotonous: the two former are effected by the elevation and depreffion, that is, the raifing and falling of the voice, and the latter by a repetition of the fame tone.

Measure relates to the continuance or fuftentation of the founds longer or fhorter, and is called time.

Mufical Notes, their Names, and Keys.

Height, depth and measure are expressed, or represented artificially to the eye, by certain marks, called notes,

in mufical language named breve, femibreve, minim, crotchet, quaver, femiquaver, femidimiquaver, placed upon five parallel lines one over another, and between the spaces, afcending and defcending on them, flow or faft, as so many steps; hence the name fcale, or gamut, denominated gamut, are, bmi, cfaut, dfolre, elami, efaut, gfolreut, or their initial letters, g, a, b, c, d, e, f, g, confined with perpendicular lines called bars, thus,

a b c d e f g gf edc bag

Here

Here g, a, b, c, d, e, f, beginning on the fecond line, and afcending to the fifth, anfwer to the feven tones in mufick, g repeated on the space above, being the octave to g below, not the unifon, as fome improperly call it. For unifons are exactly one and the fame tones, as when a number of boys or women fing together the fame tune; whereas in octaves the voices and inftruments are of different forts, either by themselves, or joining with the fopranos.

Each of these letters hath its peculiar and proper modulation; of which fuch letter is the denominator and guide, therefore called the key or fundamental note of any tune, melody, or harmony.

The divifion of Sounds into half, quarter

Sounds or tones have another very curious property, that of divifibility, to be diftinguished only by a skilful ear, and with mathematical precifion by means of an instrument conftructed of one string, therefore called a monochord.