bridges_counterpoint:fourth_species_in_two_parts

Counterpoint (Bridge): Chapter 4

Two 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 should commence with a half-bar's rest, the last bar should contain a note of equal value with the cantus firmus.

As in the preceding species, the first note of the counterpoint must be a perfect concord 1), and the second note of each following bar must be a concord either perfect or imperfect. These concords are syncopated or suspended into the following bar. The first note of each bar is thus generally tied to the second note of the preceding bar, and may be, and in fact as often as possible should be, a discord. This prepared discord must resolve by falling one degree, the note to which it falls being a concord. Should the syncopated note, however, be a concord, we may of course move from it by skip.

The dissonances of the fourth, seventh, and ninth (not the second) may be used above the cantus firmus, the seventh being preferred in two-part counterpoint. The second and fourth may be used below the cantus firmus, the second being preferred.

There are cases when a perfect fifth must be treated as a discord 2), viz. when it is clearly a “retardation” of a sixth. It will resolve by ascending one degree (Ex. 40, a).

In the retardation of a sixth in a minor key an augmented fifth is occasionally used, but this is rare (Ex. 40, b).

The diminished fifth may be used as a suspension, the resolution being deferred for one note, and the syncopation interrupted, the counterpoint being then in the second species.

The interpolation of the second species is often most useful in other places besides when following a diminished fifth as above, helping us to avoid tiresome repetitions. The interruption of the syncopation should not exceed two minims 3).

Passages which would be incorrect without suspensions are equally incorrect with them. The following progressions are bad, being only disguised consecutives 4) ; that at a, without the syncopation, would be a “hidden” fifth, and must be avoided in two-part:

Forbidden parallels

The best cadences are:

If three notes to one be written, the second note may be either a concord or passing discord. The ornamental resolution of suspensions (see Chapter 5, second paragraph), may also be employed, and will frequently be found useful at the cadence.

Some authors recommend the combination of the second and fourth species, instead of treating them separately. This is of course merely a development of par. 54 5). For an example, see Ex. 46.

Ex. 45: The cadence is somewhat uncommon, the cantus firmus rendering the usual 7-6 on the penultimate bar inadvisable.

Ex. 46: In this example the second species is used so often it may be considered a specimen of the combination of the second and fourth species.

Ex. 47: The numerous fifths are not, strictly speaking, incorrect, as may be seen by referring to Ex. 14 6), which is Ex. 47 without the syncopations. The student is advised to be sparing in his use of such fifths, at least in two-part counterpoint.

Ex. 51: An example in triple meter, the cadence by the aid of an ornamental resolution. The cantus firmus begins on the dominant.

Ex. 52: The E-flat in bar 5 avoids the tritone which would have existed between E-natural and the following B-flat, and introduces a satisfactory modulation to the subdominant. In bar 9 the diminished fifth is used, the resolution being deferred.

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1)
consonance
2)
dissonance
3)
half-notes
4)
parallels
5)
The interpolation of the second species is often most useful in other places besides when following a diminished fifth as above, helping us to avoid tiresome repetitions. The interruption of the syncopation should not exceed two minims.
  • bridges_counterpoint/fourth_species_in_two_parts.txt
  • Last modified: 2018/01/30 18:31
  • by brian