Beauty, has obtained
the sole Privilege of being heard often without tiring, provided it does
not go beyond the Limits prescrib'd by Professors of good Taste.

Sec. 2. From the Time that the _Appoggiatura_ has been invented to adorn
the Art of Singing, the true Reason,[18] why it cannot be used in all
Places, remains yet a Secret. After having searched for it among Singers
of the first Rank in vain, I considered that Musick, as a Science, ought
to have its Rules, and that all Manner of Ways should be tried to
discover them. I do not flatter myself that I am arrived at it; but the
Judicious will see, at least that I am come near it. However, treating
of a Matter wholly produced from my Observations, I should hope for more
Indulgence in this Chapter than in any other.

Sec. 3. From Practice, I perceive, that from _C_ to _C_ by _B Quadro_,[19]
a Voice can ascend and descend gradually with the _Appoggiatura_,
passing without any the least Obstacle thro' all the five _Tones_, and
the two _Semitones_, that make an _Octave_.

Sec. 4. That from every accidental _Diezis_, or Sharp, that may be found in
the Scale, one can gradually rise a _Semitone_ to the nearest Note with
an _Appoggiatura_, and return in the same Manner.[20]

Sec. 5. That from every Note that has a _B Quadro_, or Natural, one can
ascend by _Semitones_ to every one that has a _B Molle_, or Flat, with
an _Appoggiatura_.[21]

Sec. 6. But, contrarywise, my Ear tells me, that from _F_, _G_, _A_, _C_,
and _D_, one cannot rise gradually with an _Appoggiatura_ by
_Semitones_,[22] when any of these five _Tones_ have a Sharp annex'd to
them.

Sec. 7. That one cannot pass with an _Appoggiatura_ gradually from a third
_Minor_ to the Bass, to a third _Major_, nor from the third _Major_ to
the third _Minor_.[23]

Sec. 8. That two consequent _Appoggiatura's_ cannot pass gradually by
_Semitones_ from one _Tone_ to another.[24]

Sec. 9. That one cannot rise by _Semitone_, with an _Appoggiatura_, from
any Note with a Flat.[25]

Sec. 10. And, finally, where the _Appoggiatura_ cannot ascend, it cannot
descend.

Sec. 11. Practice giving us no Insight into the Reason of all these Rules,
let us see if it can be found out by those who ought to account for it.

Sec. 12. Theory teaches us, that the abovementioned _Octave_ consisting of
twelve unequal _Semitones_, it is necessary to distinguish the _Major_
from the _Minor_, and it sends the Student to consult the _Tetrachor