THE ART of DESCANT: OR Composing Musick in Parts.
PART II. Of Tones of Musick.
OF all things that belong to the making up of a Musician, the most necessary and useful one for him is the true knowledge of the Key or Mood, or Tone, for all signifie the same thing, with the Closes belonging un∣to it, for there is no Tune that can have any grace or sweetness unless it be bounden with∣in a proper Key, without running into strange Keys, which have no affinity with the Ayr of the Song. I have therefore thought good in an easie and brief discourse to endeavour to express that which many in large and obscure Volumes have made fearful to the idle Reader.
The first thing herein to be considered is the eighth, which is equally divided into a fourth, and a fifth, as thus: Page 28 The8 〈♫〉 The 4. The 5.
Here you see the fourth in the upper place, and the fifth in the lower place, which is called Modus Authentus: But contrary thus: The 8 〈♫〉 The 5. The 4.
This is called Modus Plagalii, but howsoever the fourth in the eighth is placed, we must have our eye on the fifth, for that only discovers the Key, and all the Closes pertaining pro∣perly thereunto: This fifth is also divided into two thirds, sometimes the lesser third hath the upper place, and the greater third supports it below, sometimes the greater third is higher, and the lesser third rests in the lowest place: as for Example: 〈♫〉 The lesser 3. The greater 3. 〈♫〉 The greater 3. The lesser 3.
The lowest Note of this fifth bears the name of the Key, as if the eighth be from G to G, the fifth from G beneath to D above, G being the lowest Note of the fifth, shews that G is the Key; and if one should demand in what Key your Song is set, you must answer in Gam-vt, or G sol re vt, that is, in G.
Page 29If the compass of your Song should fall out thus: 〈♫〉
Respect not the fourth below, but look to your fift above, and the lowest Note of that fift assume for you Key, which is C, then di∣vide that fift into its two 3ds, and so you shall find out all the closes that belong to that Key.
The main and fundamental close is in the Key it self, the second is in the upper Note of this fift, the third is in the upper Note of the lowest third, if it be the lesser third; as for example, if the Key be in G, with B flat, you may close in these three places.
〈♫〉 〈♫〉
The first close is that which maintains the Ayr of the Key, and may be used often, the second is next to be preferr'd, and third last.
But if the Key should be in G with B sharp, then the last close being to be made in the greater or sharp third, is unproper, and therefore for variety sometime the next Key above is joyned with it, which is A, and some∣times the fourth Key, which is C. But these Page 30 changes of Keys, must be done with judge∣ment, yet I have aptly closed in the upper Note of the lowest third of the Key, the Key being in F, and the upper Note of the third standing in A, as you may perceive in this Ayr.
1 〈♫〉 〈♫〉 2 3 〈♫〉 〈♫〉 4 〈♫〉 〈♫〉
In this Ayr the first Close is in the upper Note of the fifth, which from F is C, the se∣cond Close is in the upper Note of the great third, which from F is A.
But the last and final Close is in the Key it self, which is F, as it must ever be, whereso∣ever Page 31 your Key shall stand, either in G, or C, or F, or elsewhere, the same rule of the fifth is perpetual, being divided into thirds, which can be but two ways, that is, either when the upper third is less by half a Note than the lower, or when the lower third contains the half Note, which is Mi fa, or La Fa.
If the lower third contains the half Note, it hath it either above, as La Mi Fa; La Mi being the whole Note, and Mi Fa but half so much, that is the half Note; or else when the half Note is underneath, Mi Fa Sol; Mi Fa is the half Note, and Fa Sol is the whole Note; but whether the half Note be uppermost or lowermost, if the lowest third of the fifth be the lesser third, that Key yields familiarly three closes; example of the half Note, standing in the upper place was shew∣ed before, now I will set down the other.
〈♫〉 〈♫〉
But for the other Keys that divide the fifth, so that it hath the less third above, and the greater underneath, they can challenge Page 32 but two proper closes, one in the lowest Note of the fift, which is the fundamental Key, and the other in the uppermost Note of the same, wherein also you may close at plea∣sure. True it is, that the Key next above hath a great affinity with the right Key, and may therefore, as I said before, be used, as also the fourth Key above the final Key.
Examples of both in two beginnings of Songs. 1 〈♫〉 〈♫〉 2 〈♫〉 〈♫〉
In the first Example A is mixt with G, and in the second C is joyned with G, as you may understand by the second closes of both.
To make the Key known is most necessary in the beginning of a Song, and it is best ex∣prest by the often using of his proper fift, and fourth, and third, rising or falling.
