In music, consecutive fifths (sometimes known as parallel fifths) are progressions in which a perfect fifth is followed by a different perfect fifth between the same two musical parts (or voices): for example, from C to D in one part along with G to A in a higher part. Intervening octaves are irrelevant to this aspect of musical grammar; for example, parallel twelfths (i.e., as created by successive intervals of an octave plus a fifth) are equivalent to parallel fifths.

In the medieval period, large church organs and positive organs would often be permanently arranged for each single key to speak in a consecutive fifth. It is believed this practice dates to Roman times. A positive organ having this configuration has been reconstructed recently by Van der Putten and is housed in Groningen, and is used in an attempt to rediscover performance practice of the time.

During the common practice period, the use of consecutive fifths was strongly discouraged. This was primarily due to the notion of voice leading, which stresses the individual identity of the parts. Because of the powerful presence of the fifth above the fundamental in the overtone series, the individuality of two parts is weakened when they move in parallel fifths.

Development of the prohibition

Singing in consecutive fifths may have originated from the accidental singing of a chant a perfect fifth above (or a perfect fourth below) the proper pitch. Whatever its origin, singing in parallel fifths became commonplace in early organum and conductus styles. Around 1300, Johannes de Grocheo became the first theorist to prohibit the practice. However, parallel fifths were still common in 14th-century music. The early 15th century composer Lionel Powers likewise forbade the motion of "2 acordis perfite of one kynde, as 2 unisouns, 2 5ths, 2 8ths, 2 12ths, 2 15ths," and it is with the transition to Renaissance-style counterpoint that the use of parallel perfect consonances was consistently avoided in practice.

Composers avoided writing consecutive fifths between two independent parts, such as tenor and bass lines.

The fifths did not have to be undisguised, or the only two notes of a melodic line. The interval may form part of a chord of any number of notes, and may be set well apart from the rest of the harmony, or finely interwoven in its midst. But the interval was always to be quitted by any movement that did not land on another fifth.

The prohibition concerning fifths did not just apply to perfect fifths. Some theorists objected also to the progression from a perfect fifth to a diminished fifth in parallel motion; for example the progression from C and G to B and F (B and F forming a diminished fifth).

The strict avoidance of consecutive fifths is one of the major reasons some musicologists doubt whether Johann Sebastian Bach composed the famous Toccata and Fugue in D minor. Bach was an accomplished composer, highly skilled at avoiding consecutive fifths, but the toccata abounds with them. However, more recent arguments suggest this is not the case at all, and that the Toccata was written by Bach but written for violin and transcribed for organ.

The identification and avoidance of perfect fifths in the instruction of counterpoint and harmony help to distinguish the more formal idiom of classical music from popular and folk musics, in which consecutive fifths commonly appear in the form of double tonics and shifts of level. The prohibition of consecutive fifths in European classical music originates not only in the requirement for contrary motion in counterpoint but in a gradual and eventually self-conscious attempt to distance classical music from folk traditions. As Sir Donald Tovey explains in his discussion of Joseph Haydn's Symphony no. 88, "The trio is one of Haydn's finest pieces of rustic dance music, with hurdy-gurdy drones which shift in disregard of the rule forbidding consecutive fifths. The disregard is justified by the fact that the essential objection to consecutive fifths is that they produce the effect of shifting hurdy-gurdy drones.

In the course of the 19th century consecutive fifths became more common, arising out of new textures and new conceptions of propriety in voice leading generally. They even became a stylistic feature in the work of some composers, notably Chopin; and with the early 20th century and the breakdown of common-practice norms the prohibition became less and less relevant. (See below for later developments.)

Related progressions

Parallel octaves and fourths

Consecutive fifths are avoided in part because they cause a loss of individuality between parts. This lack of individuality is even more pronounced when parts move in parallel octaves or in unison. These are therefore also generally forbidden among independently moving parts.

The literature deals with consecutive perfect fourths less systematically, but theorists have often restricted their use. Theorists commonly disallow consecutive perfect fourths involving the lowest part, especially between the lowest part and the highest part. Due to the complexity of the ratio between frequencies of the perfect fourth, the interval is considered dissonant when set against the bass. (See Consonance and dissonance.) Since the beginning of the common practice period, is has been theorized that all dissonances should be properly resolved to a perfect consonance (there are few exceptions). Therefore, parallel fourths are generally dismissed in voice leading as a series of consecutive unresolved dissonances.

Hidden consecutives

So-called hidden consecutives, also called direct or covered octaves or fifths, occur when two independent parts approach a single perfect fifth or octave by similar motion instead of oblique or contrary motion. A single fifth or octave approached this way is sometimes called an exposed fifth or exposed octave. Conventional style dictates that such a progression be avoided; but it is sometimes permitted under certain conditions, such as the following: the interval does not involve either the highest or the lowest part, the interval does not occur between both of those extreme parts, the interval is approached in one part by a semitone step, or the interval is approached in the higher part by step. The details differ considerably from period to period, and even among composers writing in the same period.

Special uses and exceptions in early music

Consecutive fifths are typically used to evoke the sound of music in medieval times or exotic places. The use of parallel fifths (or fourths) to refer to the sound of traditional Chinese or other kinds of Eastern music was once commonplace in film scores and songs. Since these passages are an obvious oversimplification and parody of the styles that they seek to evoke, this use of parallel fifths declined during the last half of the 20th century.

In Iceland, the traditional song style known as tvísöngur, "twin-singing", goes back to the Middle Ages and is still taught in schools today. In this style, a melody is sung against itself, typically in parallel fifths.

Georgian music frequently uses parallel fifths, and sometimes parallel major ninths above the fifths. This means that there are two sets of parallel fifths, one directly on top of the other. This is especially prominent in the sacred music of the Guria region, in which the pieces are sung a cappella by men. It is believed that this harmonic style dates from pre-Christian times.

Consecutive fifths (as well as fourths and octaves) are commonly used to mimic the sound of Gregorian plainsong. This practice is well-founded in early European musical traditions. Plainsong was originally sung in unison, not in fifths, but by the ninth century there is evidence that singing in parallel intervals (fifths, octaves, and fourths) commonly ornamented the performance of chant. This is documented in the anonymous ninth-century theory treatises known as Musica enchiriadis and its commentary Scolica enchiriadis. These treatises use Daseian music notation, based on four-note patterns called tetrachords, which easily notates parallel fifths. This notation predates Guido of Arezzo's solmization, which divides the scale into six-note patterns called hexachords, and the modern octave-based staff notation into which Guido's gamut evolved.

Mozart fifths

In progressions involving chromatic chords, consecutive fifths moving by semitone are sometimes considered acceptable. There may be other factors in the management of the progression that take priority; and in any case the supposed strangeness of the consecutives is masked by the unusual quality of the progression as a whole. Especially when consecutive fifths involve the German augmented sixth chord, they are called Mozart fifths, because of their use by that composer.

An ingenious illustration is b.69 of Contrapunctus XI from Die Kunst der Fuge, composed by J. S. Bach.

Parallel fifths in modern music

• Composer Philip Glass, who studied under Nadia Boulanger, wrote a piece called "Music in Fifths" that uses parallel fifths throughout the piece. This piece was meant as tribute to her teachings of never using parallel fifths.
• In his famous "Adagio for Strings" Samuel Barber makes parallel fifths, for example in measures 5 and 6 in the cellos (there also is a parallel octave with the first violins).

External links

• Hopkins, Pandora and Thorkell Sigurbjörnsson: Iceland, Grove Music Online ed. L. Macy (Accessed 8 June 2006), Grove Music - Access by subscription only

Notes

References

• Jeppeson, Knud. Counterpoint: the polyphonic vocal style of the sixteenth century, English translation 1939, reprint by Dover, NY, 1992. ISBN 0-486-27036-X.
• Meech, Sanford. "Three Musical Treatises in English from a Fifteenth-Century Manuscript", Speculum X.3, July 1935.
• Tovey, Donald Francis. Essays in musical analysis, vol. 1, p. 142. Quoted in van der Merwe, Peter (1989). Origins of the Popular Style: The Antecedents of Twentieth-Century Popular Music. Oxford: Clarendon Press. ISBN 0-19-316121-4.