§ 7. The second is the Shake Minor, consisting of a Sound, and its neighbouring Semitone Major; and where the one or the other of these, two Shakes are proper, the Compositions will easily shew. From the inferior or lower Cadences, the first, or full Tone Shake is for ever excluded.[33] If the Difference of these two Shakes is not easily discovered in the Singer, whenever it is with a Semitone, one may attribute the Cause to the want of Force of the Auxiliary to make itself heard distinctly; besides, this Shake being more difficult to be beat than the other, every body does not know how to make it, as it should be, and Negligence becomes a Habit. If this Shake is not distinguished in Instruments, the Fault is in the Ear.[34]
§ 8. The third is the Mezzo-trillo, or the short Shake, which is likewise known from its Name. One, who is Master of the first and second, with the Art of beating it a little closer, will easily learn it; ending it as soon as heard, and adding a little Brilliant. For this Reason, this Shake pleases more in brisk and lively Airs than in the Pathetick.[35]
§ 9. The fourth is the rising Shake, which is done by making the Voice ascend imperceptibly, shaking from Comma to Comma without discovering the Rise.[36]
§ 10. The fifth is the descending Shake, which is done by making the Voice decline insensibly from Comma to Comma, shaking in such Manner that the Descent be not distinguished. These two Shakes, ever since true[37] Taste has prevailed, are no more in Vogue, and ought rather to be forgot than learn'd. A nice Ear equally abhorrs the ancient dry Stuff, and the modern Abuses.
§ 11. The sixth is the slow Shake, whose Quality is also denoted by its Name. He, who does not study this, in my Opinion ought not therefore to lose the Name of a good Singer; for it being only an affected Waving, that at last unites with the first and second Shake, it cannot, I think, please more than once.[38]
§ 12. The seventh is the redoubled Shake, which is learned by mixing a few Notes between the Major or Minor Shake, which Interposition suffices to make several Shakes of one. This is beautiful, when those few Notes, so intermixed, are sung with Force. If then it be gently formed on the high Notes of an excellent Voice,[39] perfect in this rare Quality, and not made use of too often, it cannot displease even Envy itself.
§ 13. The eighth is the Trillo-Mordente, or the Shake with a Beat, which is a pleasing Grace in Singing, and is taught rather by Nature than by Art. This is produced with more Velocity than the others, and is no sooner born but dies. That Singer has a great Advantage, who from time to time mixes it in Passages or Divisions (of which I shall take Notice in the proper Chapter). He, who understands his Profession, rarely fails of using it after the Appoggiatura; and he, who despises it, is guilty of more than Ignorance.[40]
§ 14. Of all these Shakes, the two first are most necessary, and require most the Application of the Master. I know too well that it is customary to sing without Shakes; but the Example, of those who study but superficially, ought not to be imitated.
§ 15. The Shake, to be beautiful, requires to be prepared, though, on some Occasions, Time or Taste will not permit it. But on final Cadences, it is always necessary, now on the Tone, now on the Semitone above its Note, according to the Nature of the Composition.
§ 16. The Defects of the Shake are many. The long holding-out Shake triumph'd formerly, and very improperly, as now the Divisions do; but when the Art grew refined, it was left to the Trumpets, or to those Singers that waited for the Eruption of an E Viva! or Bravo! from the Populace. That Shake which is too often heard, be it ever so fine, cannot please. That which is beat with an uneven Motion disgusts; that like the Quivering of a Goat makes one laugh; and that in the Throat is the worst: That which is produced by a Tone and its third, is disagreeable; the Slow is tiresome; and that which is out of Tune is hideous.