Two-Part Counterpoint

In this order of counterpoint, two minims ¹⁾ should be placed over every semibreve ²⁾ of the cantus firmus, except for the last bar, where a semibreve ³⁾ should always be put against a semibreve ⁴⁾.

The first part of the bar which is occupied by a minim ⁵⁾, is called the accented part of the bar; and the second part occupied equally by another minim ⁶⁾, is called the unaccented part of the bar.

The accented part of the bar should be in concord ⁷⁾; although there are cases, where this may allow for variation, – that is to say, by employing a discord ⁸⁾ at the accented part of the bar; but this can only be in certain dilemmas, either that the melody shall not be too disjunct, or to avoid other objectionable points.

The unaccented part of the bar may consist of a concord ⁹⁾, or else of a discord ¹⁰⁾, provided this latter be introduced between two concords ¹¹⁾, and that the movement of the melody be conjunct. In such a case, this discord ¹²⁾ is called a passing tone.

The accented parts of the bar are not in this order subjected to Rule 4; provided, however, that the infraction of that rule be corrected in the unaccented part, – by which is meant: Firstly, that the unaccented parts shall strike another concord ¹³⁾. Secondly, that from the accented part of the bar to the unaccented, the procedure shall be by an interval of more than a third. Thirdly, that in proceeding from the accented to the unaccented part, it shall be by contrary movement.

Demonstrations – It shall now be seen, whether, in fulfilling the prescribed conditions, several consecutive ¹⁴⁾ fifths might be saved.

Fault (parallel fifths) according to Rule 4:–

By observing the conditions of Rule 11, the melody can only be arranged thus:–

For it is prohibited to be written thus:–

It follows, then, from these two methods, that the fifths are not saved; firstly, because in Example 34, the unison which occurs on the unaccented parts of the bars, cannot, on account of its nullity, either mitigate, or destroy, the effect of the fifth which precedes it, nor of that which follows it; secondly, because in Example 35, the interval of a third which intervenes between the accented and unaccented part of the bar, is too insignificant to work the desired effect.

There is a method by which several consecutive ¹⁵⁾ fifths may be saved; thus:–

But this method is harsh and bold, inasmuch as between the first unaccented part and the second accented part, there occurs a movement prohibited by Rule 6. This expedient, therefore, is available to save two consecutive ¹⁶⁾ fifths only, and not more; and even then, it must be in cases where the melody and the harmony violate no rule.

It may now be examined, whether, under favor of the precribed conditions, several successive octaves can be saved.

Fault (parallel octaves) according to Rule 4:–

By observing Rule 11, these means may not be employed:–