On Imitation

The other sorts of imitation which remain to be mentioned are:

• Imitation by augmentation
• Imitation by diminution
• Imitation with reversed accents
• Interrupted imitation
• Convertible imitation
• Periodic imitation
• Canonic imitation

All these imitations may be created alternately with the four movements indicated, and may be treated regularly, or irregularly; provided this can be done, however, without falling into defects that would fetter the melody or the harmony.

Observation – The limitations, heretofore cited, as well as their denominations, are taken from the Treatise on Fugue and Counterpoint by Friedrich Wilhelm Marpurg, which can be consulted for instruction and knowledge of such imitations as may have been omitted here. Marpurg's work ¹⁾, with regard to Imitations, Fugues, etc, as well as to all devices of composition, is one of the most complete of the kind known, which is the reason of its being so much esteemed for reference.

Imitation by augmentation takes place when the antecedent proposes a theme, and when the consequent response note for note, while augmenting the value of each note.

Imitation by diminution takes place when the consequent diminishes the value of the notes which constitute the imitation.

Imitation with reversed accents is that which is created when the parts follow each other upon opposite portions of the bar; that is to say, when one part commences upon the accented portion of the bar, and the other response by commencing upon the unaccented portion. It is frequently by the employment of syncopation, that this device is obtained.

Interrupted imitation is created by suspending – through the medium of rests in the consequent – the continued progression of the notes proposed by the antecedent.

Convertible imitation is the name given to a period written in such a way that the parts may be inverted without any change; that is to say, the upper part may become the lower part, or the lower part may become the upper. In order to secure such a way, care must be taken never to employ the interval of a fifth: when a fifth is inverted, this interval produces a fourth. This kind of imitation is referred to as a double counterpoint, as will be seen in the next chapter.

Examples of convertible imitation

Periodic imitation takes place when a portion only of the melody or theme proposed by the antecedent is imitated. Here are two examples:

Canonic imitation is that where the consequent responds to the antecedent, note for note, from beginning to end. This imitation, by its very denomination, becomes that is called Canon, may be treated in two ways:

1. Finite, when it is finished by a coda, or conclusion
2. Infinite (or circular), when it is combined in such a manner as to return from the end of the imitation to the beginning, without ceasing.

Example of finite canonic imitation

Example of infinite canonic imitation

The student should endeavor, as much as possible, to practice all of these imitations, by all the movements, and in all the intervals. What has been demonstrated in the first and second section, with respect to imitations, must suffice; and now, imitations in three and in four parts will be discussed.