Three-Part Counterpoint

Three-part counterpoint is not so strict as two-part counterpoint. It may even be said that rigorous strictness, belongs, in fact, only to this latter. The severity of the rules relaxes, in proportion as the difficulties multiply; and these difficulties increase in exact ratio with the number of parts that are made to progress together. Nevertheless, this is no reason for the entire emancipation from the severity which marks the kind of composition in question; for there is a wide difference between the facilities granted to this kind of composition, and those which have been assumed in the system of modern music.

In this order ¹⁾, the harmony should be complete in each bar, as often as may be, without rendering the melody too disjointed, and consequently too difficult. It will therefore sometimes be necessary, instead of always employing complete chords, to suppress a note of a chord, and double one of those that remain, in order to obtain a more-flowing melody in the parts, and at the same time more variety of effect,– a variety which is produced by the mixture of complete chords and incomplete chords.

Each chord of this example is complete; but although the parts sing tolerably well, they sing still better in the following example, where the chords are not complete throughout:–

Example 82, less complete than Example 81, is, for that very reason, more easy as well as more elegant.

The first bar should, generally speaking, consist of the common chord; it may, however, happen – on account of the diapason or compass of the voices, or else on account of the bar which follows,– that instead of employing the common chord (thus root - third - fifth stacked from the bottom upward), it may be necessary to use it thus: 1-5-3 ²⁾, and even to curtail it of some of its members. In such a case, the following forms of usage may be adopted:

• as 1-8-3 (root, then octave, and then third from the bottom-up)
• as 1-3-8
• as 1-8-5
• as 1-5-8
• as 1-8-8

This latter (1-8-8), from offering throughout the same sound, produces the same effect as the unison. It is permitted to commence in this manner.

As to employing the common chord in the last bar, these are the forms to be adopted:

• 1-1-1
• 1-8-8
• 1-5-8
• 1-8-5
• 1-1-5

These forms may be used as much as possible, but it is frequently difficult, and sometimes even impossible, to employ either of these forms when the cantus firmus lies in the lower part; and in this case, the third and the octave must be used at the cadence in the final bar. The ancient composers usually finished with the major third, whatever might be the nature of the principal key ³⁾; and they gave as a reason, that the minor third being more imperfect than the major third, the latter was preferable at the cadence.

The parts should be preserved at a suitable distance from one another, but the nearer they approach, the better will be the effect they produce. There are eases where this rule admits of exceptions; but the endeavour should be to use them rarely, and so to manage as to avoid their necessity, unless this is absolutely impossible. In order to facilitate the means of observing this rule, it is permitted, in a difficult position, to make one of the upper parts pass below a lower part.

It is prohibited, in three-part counterpoint, as in two-part counterpoint, to make concealed fifths or octaves either between the intermediate part and one of the two other parts.

It is allowable, but very rarely, to deviate from this rule (as regards the intermediate part alone) in a case where the strict observance of this prohibition would impede the progress of the two other parts, or give rise to some still greater objection in the following bar.

There is no exception, as regards the extreme parts with each other.

Observation – It is useless to mention here the rule which prohibits the two fifths and two octaves in succession, since this rule applies to all kinds of composition.

In like manner, the prohibition against the introduction of two concealed fifths or octaves between the two extreme parts, holds good likewise in all kinds of strict composition.

In the employment of incomplete chords, the third or the sixth must not be heard in two parts at a time. It is prohibited to double the one or the other, on account of their imperfection, and because they impoverish the harmony. The doubled fifth or octave are tolerated in the employment of incomplete chords on account of their perfection. This rule, nevertheless, is subject to many exceptions; and there are several cases, in which, for the sake of good harmony, and in order to effect a judicious procedure of the parts, in short, to avoid important faults, the doubling of imperfect concords ⁴⁾ is allowed, if all means of managing otherwise have been tried in vain.

Example of this rule strictly followed

The upper parts should never form fourths with the lower part; consequently, the chord of the fourth and sixth ⁵⁾ must never be employed. A fourth between the intermediate part and the upper part is tolerated, as, for example, in the chord 1-6-3 (from the bottom upward) or in the incomplete common chord, according to this form: 1-5-8, as it may be employed in the first bar and in the last bar.

The chord should always be complete in the penultimate bar.

In conclusion, an example of a lesson in three parts, of this order ⁶⁾, is here presented to the view of the student:–