On Imitation

In order to have a fixed starting point in this kind of imitation, the composers in the classical style of writing, availed themselves of the following method: they placed opposite to a scale composed of an octave (for instance, the scale of C), commencing by the tonic, the same series of sounds in a contrary direction, thus:

By this method, is obtained, free imitation by contrary movement, as shown in the following example:

This method may serve for the major mode, and for the relative-minor mode.

For irregular imitation by contrary movement, the following scale opposed to itself may be used; and this method can be applied to the major mode, and to the minor mode:

Example of this scale

This scale gives the imitation denoted in the following example:

It may be seen, by these examples, that in the system of the first scale, when the antecedent commences the imitation by a C, the consequent must respond to the C by one in the octave; if the antecedent commences by a B, a G, or an A, the consequent must respond by a D, an E, or an F, etc. In the system of the second scale, when the antecedent commences by a C, a G, or an E, the consequent must respond by a C, a C, or an E, etc; once let the first note of the response be found, and all the other notes naturally follow.

For this kind of imitation, it is necessary to adopt a method like the one employed with respect to irregular imitation; but the scales which must be placed opposite to each other upon this occasion are different. They must be two scales in which the semitones occur upon the same degrees; so that in the imitation of the tones and the semitones, they shall correspond exactly.

In order to find the same correspondence of tones and semitones in the minor mode, this is the way in which this scale must be disposed:

Example of regular imitation by contrary movement

It is needless to observe that each time there is a change of key, these given scales must always be referred to the key in which the imitation is made, both for major modes and minor modes.

All that has just been said, applies equally to retrograde imitation by contrary movement, which also may be regular or irregular.

Retrograde contrary imitation, which consists in commencing with the last note and retrograding towards the first, pursuing a contrary movement, may be created in two ways: 1) bar by bar, or 2) period by period.

Here are examples of these two kinds of imitation, which will explain their mechanism better than words:

Examples of “bar by bar” retrograde contrary imitation

Examples of “period by period” retrograde contrary imitation

Examples have just been given of several methods of treating retrograde imitation by contrary movement; as to that by similar movement, the mere remark may be made, that it can take place upon all the intervals, as is the case with the imitations of which the first section consists. Examples on this branch of the study may be dispensed with; as pupils will take pains to practice themselves in it, by searching for methods of accomplishing their object, without the aid of models. Besides, these retrograde imitations by similar movement, are not so difficult of treatment as those which have been shown in the above examples.

Such are the rules of the four principal ways of treating imitation:

1. By similar movement
2. By contrary movement
3. By retrograde similar movement, and
4. By retrograde contrary movement.