Counterpoint (Bridge): Chapter 3

Four notes are here written in the counterpoint to every one of the cantus firmus with the exception of the first and last. The first bar of the counterpoint usually commences with a crotchet 1) rest; the last bar must contain a note of equal value with the cantus firmus.

As in the second species, the first note of the counterpoint must be a perfect concord 2), and the first note of every following bar (with the license allowed in par. 30 3)) either a perfect or imperfect concord, the latter being preferred. The remaining notes may be either consonant or dissonant, the latter being approached and quitted by conjunct degrees. When consistent with good flowing counterpoint, the third note in each bar should be a concord. This rule may, however, be freely disregarded for the sake of a melodious progression.

It is necessary to warn the student that a note may be consonant with the cantus firmus, and yet, by reason of the implied harmony, must be treated as a discord, i.e. “approached and quitted by conjunct degrees.” Thus in Ex. 30, bar 1, the implied harmony is a 5/3 FIXME on C. The last crotchet 4), A, being therefore dissonant, is wrongly quitted. Two different chords may of course be taken in every bar in this species; but when this is the case the second chord must appear upon the second or third crotchet, and not (as is the case in Ex. 30) upon the fourth.

Skips should be avoided as much as possible, because of the small value of the notes of the counterpoint.

Particular care should be taken, after the use of three or four notes alphabetically, to avoid a skip, even of a third, in the same direction, more especially to an accented note. The melody will gain much by making the skip at the beginning of the passage.

The unison may be more freely used in this and the other species yet to be explained. Care should be taken to use it only at the weak part of the bar, and not at the accent.

Similar perfect concords should not appear upon the accented notes of successive bars, nor upon the third crotchet of one bar and the first of the next. They are not so objectionable upon unaccented notes, unless these are the highest (if the counterpoint be above) or the lowest (if the counterpoint be below) in two successive bars.

The skip of an augmented fourth, or tritone, is of course to be avoided, nor should the notes forming this interval appear as the first and third crotchets in a bar, or as the third in one bar and the first in the next, nor as the first and last notes of an ascending or descending passage (Ex. 31, a, b, c, d). If the passages at c and d were parts of a longer series, so that the notes forming the tritone were not at the beginning and end (and therefore not so prominent) there would be no objection to them.

Many of the older contrapuntists allowed what are called “ changing notes,” i.e. a skip from a discord on the second, and sometimes the fourth, crotchet of a bar, to a concord. Cherubini and others object to this “license,” but the judicious use of certain changing notes often gives great spirit to this species. The following are the most effective forms — those at a and b being particularly valuable at the cadence.

It will be observed in the above examples that the skip is not always made to a concord (b, c, d); and, in fact, to speak correctly, the third note in every bar of Ex. 32 is dissonant, the implied harmony at a being a sixth on D. (See note just above Ex. 30.)

There are numerous cadences, depending of course upon the position and conclusion of the cantus firmus. The following are some of the best:

The examples at a and b are of course somewhat rare, the former containing the skip of a diminished fifth, the latter (in which the cantus firmus rises to the final) a changing note.

Six or eight notes are sometimes written against one. The rules given above should be observed in attempting this counterpoint, which is merely a development of the one we have just been considering.

Ex. 34: Imperfect concords are used at the beginning of every bar except the first and last.

Ex. 35: The implied harmony in bar 13 being a 5/3 FIXME on D, the first note of the counterpoint in that bar is of course dissonant. Paragraph 30 5) will explain its appearance here.

Ex. 36: The first four bars are answered effectively by bars 5 to 8. The key is well marked at the earlier part of the example, and a modulation to the relative major is made at bar 4. The cadence is formed by the aid of the changing note.

Ex. 38 and 39 have six notes to one, the parts crossing at bar 7 of the former.

« Chapter 2 Contents Chapter 4 »

3) , 5)
Occasionally in the carrying out of a sequence, or to secure a flowing counterpoint, a discord may appear at the first part of a bar. In such a case (which should be rare) the notes immediately preceding and following the said discord should be consonant. ~ from Chapter 2
quarter note
  • bridges_counterpoint/third_species_in_two_parts.txt
  • Last modified: 2017/07/27 17:32
  • by brian