Fugue

:For the use of the word in psychology see fugue state

Characteristics and anatomy

Number of voices

The number of voices in a fugue generally ranges from three to five, but eight or even ten voices are possible in large choral or orchestral fugues. Fugues in fewer than three voices are rare, because with two voices the subject can only jump back and forth between the upper and lower voice. The best-known example of a two-voice work is the E minor fugue from Book I of Bach's Well-Tempered Clavier. Two part works which are written in a fugal manner are sometimes called "inventions".

Related Topics:
Bach's - Well-Tempered Clavier - Inventions

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The term "part" is often used in the context of the fugue as a synonym for "voice." Use of the term "voice" does not imply that the fugue in question is necessarily composed for voices rather than instruments.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Musical outline

The beginning of the fugue tends to be written to definite rules, whereas in the later portions the composer has considerably greater freedom.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

A fugue begins with an exposition of its subject by one of the voices. After the subject, a second voice "answers" the subject. The answer mimics the subject at a different pitch (interval), usually a fifth or fourth higher or lower. In a tonal answer, some of the intervals may be altered to keep the answer in the same key. In a real answer, the subject is literally transposed to another key. As the answer is passed to each new voice, the prior voice will sometimes accompany the subject with a counter-subject. It is customary for the exposition to alternate subjects (S) with answers (A) as follows: SASA. But in some fugues the order is varied: e.g. SAAS of the first fugue in Bach's Well-Tempered Clavier. The fugue's exposition concludes when all voices have stated or answered the subject.

Related Topics:
Interval - Key

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The fugue rarely stops after its initial exposition, more often continuing to one or more developmental episodes. Episodic material is usually based upon some element of the exposition - for example, a melodic motif may be taken and repeated sequentially. There may also be middle entries: these are entries of the subject by fewer than all the voices in the fugue, often varied in some way. They are often given in keys other than the tonic or dominant, or in a different mode (minor instead of major, or vice versa).

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

The episodes may also vary the subject by giving it in inversion (upside-down), retrograde (back-to-front), diminution (with shorter note values) or augmentation (with longer note values; the subject in augmentation entering in the bass is common at the end of fugues). Sometimes the voices appear in stretto, with one voice entering with the subject before the last voice has finished its entry. There also may be false entries, which begin the fugue subject, but do not give it in full (the isolated beginning is sometimes called the head motif).

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Episodes may be interspersed with repeated expositions in which all voices give subjects and answers as at the beginning of the fugue, though these may also be varied, for example by having the voices enter in a different order.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Various devices are used to form the conclusion of a fugue.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

A fugue may end with a recapitulation, in which the entries of the subject are repeated in the manner it was first introduced. Stretto entries of the subject often are found near the end, usually at the point where the fugue reaches its climax of tension. The final section often includes a pedal point, either on the dominant or the tonic note. At the very end of the fugue there may be a coda section, which follows a strong Cadence on the tonic chord.

Related Topics:
Pedal point - Dominant - Tonic - Coda - Cadence

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Timing of entries

The construction of a fugue is based on taking advantage of "contrapunctal devices" as J. S. Bach called them - places where an entrance of a theme or subject could occur. In each fugue theme, then, there is an implied structure of where and at what intervals the theme can begin in another voice. Bach was sufficiently expert that he could tell exactly what entrances could occur simply by hearing the first playing of a theme.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

Double (triple, quadruple) fugue

A double fugue has two subjects that are often developed simultaneously. Sometimes the second subject is initially presented as the counter-subject of the first, while in other examples, the second subject has its own exposition. In the latter case, the work has this structure: fugue on subject A; fugue on subject B; combination of subjects A and B. In a few cases, the second (and third, and so on) subjects may have their presentation cleverly weaved into the development (see Bach C# minor WTC I).

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

While triple fugues are not uncommon (see Bach C# minor WTC I and F# minor WTC II), quadruple fugues are rare. The surviving pages of Contrapunctus XIV from Bach's Die Kunst der Fuge represent a triple fugue that was undoubtedly quadruple in conception. Other examples quadruple fugues are the fuga IV (a quattro soggetti) from Busoni's Fantasia Contrappuntistica and in a similar respect, the quadruple fugue from Kaikhosru Sorabji's Opus Clavicembalisticum.

Related Topics:
Die Kunst der Fuge - Busoni - Fantasia Contrappuntistica - Kaikhosru Sorabji - Opus Clavicembalisticum

~ ~ ~ ~ ~ ~ ~ ~ ~ ~