Fugue

This article is about the fugue as used in music; for the psychological state, see Fugue state

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The word fugue means to flee. When applied to music, it describes a contrapuntal convention used by many composers to provide a special flavor to a musical composition. This should not be confused with the psychological term fugue state.

Fugues are generally described as being in three or more parts (there have been rare instances of a two-part fugue, however - the E minor fugue from the first book of The Well-Tempered Clavier by Johann Sebastian Bach, is one of the best known examples). Each 'part' represents a melodic voice used in the fugue.

Fugues feature a a small musical phrase or theme called the "subject", and may also feature a different small musical phrase or theme called the "counter-subject" that occasionally plays while the subject is playing.

If a fugue has a second subject, it is said to be a double-fugue.

Fugues always start with the subject played by the first voice. At some point after the first voice has started, the subject is played against by the second voice in another musical mode. Thereafter, the next voice enters with the subject in a different musical mode from the prior voice, and so on until all voices have played the subject. Typically, the first voice enters on the tonic or dominant note of the fugue's key, the second voice then answers on the dominant or tonic respectively, and so on for the remaining voices.

This describes a fugue's introduction.

A fugue may then play a bridge (where the subject is not heard at all), or it may enter into an exposition, where the subject is continuously played in various modes, ornamentations, inversions, retrogrades, or other music tricks (perhaps with an occasional bridge). One common trick is the so-called `stretto' where voices enter at a short distance from each other, one voice starting the theme before the last one has finished its entry.

The final stage of a fugue is the "recapitulation" where the subject is repeated in the manner it was first introduced (using the same musical mode and without any ornamentations). This eventually leads to the end of the fugue.

Fugues are not a true musical form, so much as a musical convention. This is reflected in the experimentation with fugue compositional techniques by jazz composers in the 20th century. While all fugues have an introduction, they may not have the other sections described above.

The 18th century composer Johann Sebastian Bach is generally regarded as the greatest composer of fugues. He often entered into contests where he would be given a subject with which to spontaneously improvise a fugue on the organ or harpsichord.

Bach's most famous works as far as fugues go are the unfinished Art of Fugue and The Well-Tempered Clavier. The former is a collection of fugues (and a few canons) on a single theme; the latter is two volumes written in different times of his life, each comprising 24 prelude and fugue pairs, one for each major and minor key. Bach also wrote smaller single fugues, and incorporated fugal writing in many of his works that were not fugues per se.

This idea of writing a cycle of fugues on all keys has been taken up by Paul Hindemith in his Ludus Tonalis, and Dmitri Shostakovich.

"Row, Row, Row Your Boat" is sometimes mistaken for a fugue, but it is actually a round, as the subject is identical for all four voices, and they repeat the subject in the same mode and key.