On Fugue

On Tonal Fugue

A so-called Tonal Fugue is a fugue of which the Subject, at its first outset, passes from the tonic to the dominant, or from the dominant to the tonic; the response, in this kind of fugue, is not identically similar to the subject, and it is governed by laws here set forth.

If the Subject commence by the tonic, and ascend or descend towards the dominant, the Response should commence by the Dominant, and descend or ascend toward the Tonic.

If the Subject commence by the Dominant, and ascend or descend towards the Tonic, the Response should commence by the Tonic, and descend or ascend towards the Dominant.

Here follow examples of Subjects more flord and more extended than the preceding ones; but still conceived on the same principle, in order that the student may become accustomed to find the exact Response to a Subject of Tonal Fugue.

Example of a subject, which from the tonic descends towards the dominant: and of the response, which from the dominant ascends towards the tonic. 1)

Example of a subject, which from the tonic descends toward the dominant; and of the response, which from the dominant descends toward the tonic.

Example of a subject, which from the dominant, descends towards the tonic; and of the response, which from the tonic, descends towards the dominant.

Example of a subject, which from the dominant ascends towards the tonic; and of the response, which from the tonic ascends towards the dominant.

Example of a subject, which from the dominant ascends towards the tonic; and of the response, which from the tonic ascends towards the dominant.

Before concluding, one remark is offered, which may serve as a guide: it is, that all the phrases of melody of a Subject, which belong to the chord or to the key of the Tonic, should be repeated in the response, in similar phrases, belonging to the chord or to the key of the Dominant; and that all the phrases of a subject, which bear analogy to the chord of the Dominant, should be repeated in the Response, in similar phrases, bearing analogy to the chord of the Tonic.

To demonstrate this, the following subject is proposed according to the immutable rule of tonal fugue:

The response is this:

But if from this simple Subject a more-complicated one is deduced according to what has been said above:

The response is:

for the two notes D, B, added between the limits of the simple interval C, G, belonging to the chord of the Dominant - that is to say, in the key of G - should be replaced in the Response by the two notes G, E, belonging to the chord of the Tonic.

Here again is another Subject:

where there should be no other change in the Response, than from the first to the second note; because the Subject, which commences by the Dominant, does not proceed towards the Tonic in the first phrase; this is the Response:

Here is another Subject, in which the melody does not proceed, in the first phrase, from the Tonic toward the Dominant; but it proceeds so at the commencement of the second phrase:

The D which terminates the first phrase, belonging naturally by its descent upon the Dominant, in the key of G, the Response should change into a G from the first note C of the Subject, in order to conform to the law of Tonal Fugue, and replace the D of the subject by a G which will descend upon C in the key into which will be transposed all the rest of the Subject in the Response:

It is superfluous to adduce a great number of Subjects; with the methods and explanations that have been demonstrated, the pupil will be enabled to find the Response to any Subject of Tonal Fugue that might offer.

On Real Fugue

Real Fugue is of more-ancient date than Tonal Fugue. It is that in which the Subject commences by the Tonic, and then proceeds towards any other chord than the Dominant; and of which the Response should be made in the fifth of the principal key, and be in all respects similar to the Subject.

The ancient composers recognized two sorts of Real Fugue: 1) Free, and 2) Limited. They called it Free, when the Response, which ought to be precisely similar to the part imitated, was not so beyond the duration of the Subject and of the Counter-Subject.

But if the Response were similar, not only to the Subject, but to all the notes of the Antecedent part from the beginning of the fugue to the end, then the Real Fugue took the name of Limited; and this sort of fugue was no other than the piece of music, to which nowadays is given the name of Canon, as has been previously said.

At present, these denominations are no longer used, and what the ancients called Free Real Fugue is the only Real Fugue adopted as a model.

It may happen that a Subject of Fugue offers, in the earliest bars, all the characters of Real Fugue, and suddenly, towards the end, terminates in Tonal Fugue. The Response should, in that case, follow the condition of the Subject; that is to say, commencing as Real Fugue, it must terminate according to the rules of Tonal Fugue.


1)
These different examples are presented under the form of stretto; that is to say, the response is brought as close as possible to the subject.
  • cherubini_counterpoint_and_fugue/on_fugue/on_tonal_fugue.txt
  • Last modified: 2018/08/10 23:16
  • by brian