Three-Part Counterpoint

This order ¹⁾ of counterpoint is subject to the same laws as the second order ²⁾ of two-part counterpoint; with this difference, however, that under favor of the two minims ³⁾ sustained by the complete common chord, two fifths placed each in the accented part of the bar may be saved, as indicated by the following example:–

The melody of the middle part, which would be prohibited in two parts, is here tolerated, on account of the higher part, the harmony of which conceals the defect of that in the middle part. This license is not admitted in the extreme parts, and although tolerated in the middle part, it should not be abused, but should be taken advantage of in the most-difficult predicaments alone.

The two minims ⁴⁾ against one semibreve ⁵⁾, should be placed in each bar in one single part only at a time; the two other parts should contain only semibreves ⁶⁾.

Doubling the third at the accented part of the bar, should be avoided; this prohibition does not hold good in the unaccented part, where the third may be doubled.

There are cases, in which the doubling of the third upon the accented part of the bar is unavoidable; but these cases are – or should be – extremely rare.

A unison upon the accented part of the bar is only permitted, when it is actually impossible to contrive otherwise; it is allowed at the first and the last bar. It is tolerated, upon the unaccented portion.

The part which introduces the two minims ⁷⁾, should commence on the unaccented part of the bar; the accented portion will be occupied by a half-rest,– it being more elegant to commence thus:–

Whether in the present order, or in those which follow, it is allowed – as was remarked in the preceding order – on occasions of emergency, to cross the parts; viz: to cause the upper part to pass below the lower. At the same time, the power to do this, is only granted for the space of one or two bars at the utmost.

It has been prohibited, in the second order ⁸⁾ of two-part counterpoint, to strike the same sound twice in the part introducing the two minims ⁹⁾. This prohibition holds good in the present order; although this rule is subject to exception, and the exception is even authorized by the example of classical authors. The exception affects the last bar but one – and no other; it is intended to obviate the objectional points which might arise out of the nature of the given cantus firmus – as in the following example:–

Counterpoint constructed in the manner shown in these two examples offers on the one hand, * the unison upon the accented part of the bar with the upper part, and on the other hand, the same objection ** with the lower part. In order to avoid these defects, here are two other examples which get rid of these objectionable points, at the same time fulfilling all the prescribed rules:–

In this way, by taking advantage of the exception just cited, the objectionable points which occur in the preceding examples are avoided; and since there exists no express law to prohibit syncopation in this order, it may be introduced without reprehension, provided it be employed no where else than in the penultimate bar. At the same time, if this discord ¹⁰⁾ can be dispensed with, it should not be used. The following examples serve to show that there are many occasions where it is very easy to avoid syncopation in the penultimate bar.