Perfect fourth

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Perfect fourth
Play (help*info) Perfect fourth on C.png
Perfect fourth Loudspeaker.svg Play  
perfect fourth
Inverse perfect fifth
Other namesdiatessaron
Semitones 5
Interval class 5
Just interval 4:3
Equal temperament 500
24 equal temperament 500
Just intonation 498

A fourth is a musical interval encompassing four staff positions in the music notation of Western culture, and a perfect fourth ( Loudspeaker.svg Play  ) is the fourth spanning five semitones (half steps, or half tones). For example, the ascending interval from C to the next F is a perfect fourth, because the note F is the fifth semitone above C, and there are four staff positions between C and F. Diminished and augmented fourths span the same number of staff positions, but consist of a different number of semitones (four and six, respectively).

In music theory, an interval is the difference in pitch between two sounds. An interval may be described as horizontal, linear, or melodic if it refers to successively sounding tones, such as two adjacent pitches in a melody, and vertical or harmonic if it pertains to simultaneously sounding tones, such as in a chord.

Western culture Norms, values and political systems originating in Europe

Western culture, sometimes equated with Western civilization, Occidental culture, the Western world, Western society, and European civilization, is the heritage of social norms, ethical values, traditional customs, belief systems, political systems, artifacts and technologies that originated in or are associated with Europe. The term also applies beyond Europe to countries and cultures whose histories are strongly connected to Europe by immigration, colonization, or influence. For example, Western culture includes countries in the Americas and Australasia, whose language and demographic ethnicity majorities are European.


The perfect fourth may be derived from the harmonic series as the interval between the third and fourth harmonics. The term perfect identifies this interval as belonging to the group of perfect intervals, so called because they are neither major nor minor (unlike thirds, which are either minor or major) but perfect.

Harmonic series (music) sequence of sounds where the base frequency of each sound is an integer multiple of the lowest base frequency

A harmonic series is the sequence of sounds—pure tones, represented by sinusoidal waves—in which the frequency of each sound is an integer multiple of the fundamental, the lowest frequency.

Minor third musical interval

In the music theory of Western culture, a minor third is a musical interval that encompasses three half steps, or semitones. Staff notation represents the minor third as encompassing three staff positions. The minor third is one of two commonly occurring thirds. It is called minor because it is the smaller of the two: the major third spans an additional semitone. For example, the interval from A to C is a minor third, as the note C lies three semitones above A, and (coincidentally) there are three staff positions from A to C. Diminished and augmented thirds span the same number of staff positions, but consist of a different number of semitones. The minor third is a skip melodically.

Major third musical interval

In classical music from Western culture, a third is a musical interval encompassing three staff positions, and the major third is a third spanning four semitones. Along with the minor third, the major third is one of two commonly occurring thirds. It is qualified as major because it is the larger of the two: the major third spans four semitones, the minor third three. For example, the interval from C to E is a major third, as the note E lies four semitones above C, and there are three staff positions from C to E. Diminished and augmented thirds span the same number of staff positions, but consist of a different number of semitones.

A perfect fourth in just intonation corresponds to a pitch ratio of 4:3, or about 498 cents ( Loudspeaker.svg Play  ), while in equal temperament a perfect fourth is equal to five semitones, or 500 cents (see additive synthesis).

Just intonation

In music, just intonation or pure intonation is the tuning of musical intervals as (small) whole number ratios of frequencies. Any interval tuned in this way is called a just interval. Just intervals and chords are aggregates of harmonic series partials and may be seen as sharing a (lower) implied fundamental. For example, a tone with a frequency of 300 Hz and another with a frequency of 200 Hz are both multiples of 100 Hz. Their interval is, therefore, an aggregate of the second and third partials of the harmonic series of an implied fundamental frequency 100 Hz.

The cent is a logarithmic unit of measure used for musical intervals. Twelve-tone equal temperament divides the octave into 12 semitones of 100 cents each. Typically, cents are used to express small intervals, or to compare the sizes of comparable intervals in different tuning systems, and in fact the interval of one cent is too small to be heard between successive notes.

Until the late 19th century, the perfect fourth was often called by its Greek name, diatessaron. [1] Its most common occurrence is between the fifth and upper root of all major and minor triads and their extensions.

Fifth (chord) chord in music theory

In music, the fifth factor of a chord is the note or pitch that is the fifth scale degree, counting the root or tonal center. When the fifth is the bass note, or lowest note, of the expressed chord, the chord is in second inversion Play .

Root (chord) note after which a chord is named

In music theory, the concept of root is the idea that a chord can be represented and named by one of its notes. It is linked to harmonic thinking— the idea that vertical aggregates of notes can form a single unit, a chord. It is in this sense that one speaks of a "C chord" or a "chord on C"—a chord built from "C" and of which the note "C" is the root. When a chord is referred to in Classical music or popular music without a reference to what type of chord it is, it is assumed a major triad, which for C contains the notes C, E and G. The root need not be the bass note, the lowest note of the chord: the concept of root is linked to that of the inversion of chords, which is derived from the notion of invertible counterpoint. In this concept, chords can be inverted while still retaining their root.

Major chord chord having a root, a major third, and a perfect fifth; e.g. C–E–G or F–A–C

In music theory, a major chord is a chord that has a root, major third, and perfect fifth. When a chord has these three notes alone, it is called a major triad. For example, the major triad built on C, called a C major triad, has pitches C–E–G:

An example of a perfect fourth is the beginning of the "Bridal Chorus" from Wagner's Lohengrin ("Treulich geführt", the colloquially-titled "Here Comes the Bride"). Other examples are the first two notes of the Christmas carol "Hark! The Herald Angels Sing" and "El Cóndor Pasa", and, for a descending perfect fourth, the second and third notes of "O Come All Ye Faithful".[ citation needed ]

<i>Lohengrin</i> (opera) opera by Richard Wagner

Lohengrin, WWV 75, is a Romantic opera in three acts composed and written by Richard Wagner, first performed in 1850. The story of the eponymous character is taken from medieval German romance, notably the Parzival of Wolfram von Eschenbach and its sequel, Lohengrin, written by a different author, itself inspired by the epic of Garin le Loherain. It is part of the Knight of the Swan tradition.

The "Bridal Chorus" from the 1850 opera Lohengrin by German composer Richard Wagner – who also wrote the libretto – is a march played for the bride's entrance at many formal weddings throughout the Western world. In English-speaking countries it is generally known as "Here Comes the Bride" or "Wedding March", though "wedding march" refers to any piece in march tempo accompanying the entrance or exit of the bride, notably Felix Mendelssohn's "Wedding March". The piece was made popular when it was used as the processional at the wedding of Victoria the Princess Royal to Prince Frederick William of Prussia in 1858.

Christmas carol music intendend for Christmastime

A Christmas carol is a carol whose lyrics are on the theme of Christmas, and which is traditionally sung on Christmas itself or during the surrounding holiday season. Christmas carols may be regarded as a subset of the broader category of Christmas music.

The perfect fourth is a perfect interval like the unison, octave, and perfect fifth, and it is a sensory consonance. In common practice harmony, however, it is considered a stylistic dissonance in certain contexts, namely in two-voice textures and whenever it appears above the bass. [2] If the bass note also happens to be the chord's root, the interval's upper note almost always temporarily displaces the third of any chord, and, in the terminology used in popular music, is then called a suspended fourth .

Unison musical parts sounding at the same pitch

In music, unison is two or more musical parts sounding the same pitch or at an octave interval, usually at the same time.

In music, an octave or perfect octave is the interval between one musical pitch and another with double its frequency. The octave relationship is a natural phenomenon that has been referred to as the "basic miracle of music", the use of which is "common in most musical systems". The interval between the first and second harmonics of the harmonic series is an octave.

Perfect fifth musical interval

In music theory, a perfect fifth is the musical interval corresponding to a pair of pitches with a frequency ratio of 3:2, or very nearly so.

Conventionally, adjacent strings of the double bass and of the bass guitar are a perfect fourth apart when unstopped, as are all pairs but one of adjacent guitar strings under standard guitar tuning. Sets of tom-tom drums are also commonly tuned in perfect fourths. The 4:3 just perfect fourth arises in the C major scale between G and C. [3] Loudspeaker.svg Play  


The use of perfect fourths and fifths to sound in parallel with and to "thicken" the melodic line was prevalent in music prior to the European polyphonic music of the Middle Ages.

In the 13th century, the fourth and fifth together were the concordantiae mediae (middle consonances) after the unison and octave, and before the thirds and sixths. The fourth came in the 15th century to be regarded as dissonant on its own, and was first classed as a dissonance by Johannes Tinctoris in his Terminorum musicae diffinitorium (1473). In practice, however, it continued to be used as a consonance when supported by the interval of a third or fifth in a lower voice. [4]

Modern acoustic theory supports the medieval interpretation insofar as the intervals of unison, octave, fifth and fourth have particularly simple frequency ratios. The octave has the ratio of 2:1, for example the interval between a' at A440 and a'' at 880 Hz, giving the ratio 880:440, or 2:1. The fifth has a ratio of 3:2, and its complement has the ratio of 3:4. Ancient and medieval music theorists appear to have been familiar with these ratios, see for example their experiments on the monochord.

Listen) with perfect (a), augmented (b) and diminished (c) fourths Notenbeispiel Quarten.gif
( Loudspeaker.svg Listen) with perfect (a), augmented (b) and diminished (c) fourths

In the years that followed, the frequency ratios of these intervals on keyboards and other fixed-tuning instruments would change slightly as different systems of tuning, such as meantone temperament, well temperament, and equal temperament were developed.

In early western polyphony, these simpler intervals (unison, octave, fifth and fourth) were generally preferred. However, in its development between the 12th and 16th centuries:

The music of the 20th century for the most part discards the rules of "classical" Western tonality. For instance, composers such as Erik Satie borrowed stylistic elements from the Middle Ages, but some composers found more innovative uses for these intervals.

Middle Ages

In medieval music, the tonality of the common practice period had not yet developed, and many examples may be found with harmonic structures that are built on fourths and fifths. The Musica enchiriadis of the mid-10th century, a guidebook for musical practice of the time, described singing in parallel fourths, fifths, and octaves. This development continued, and the music of the Notre Dame school may be considered the apex of a coherent harmony in this style.

Fourths in Guillaume Du Fay's Antiphon Ave Maris Stella AveMarisStellaDufay.png
Fourths in Guillaume Du Fay's Antiphon Ave Maris Stella

For instance, in one "Alleluia" ( Loudspeaker.svg Listen) by Pérotin, the fourth is favoured. Elsewhere, in parallel organum at the fourth, the upper line would be accompanied a fourth below. Also important was the practice of Fauxbourdon , which is a three voice technique (not infrequently improvisatory) in which the two lower voices proceed parallel to the upper voice at a fourth and sixth below. Fauxbourdon, while making extensive use of fourths, is also an important step towards the later triadic harmony of tonality, as it may be seen as a first inversion (or 6/3) triad.

This parallel 6/3 triad was incorporated into the contrapuntal style at the time, in which parallel fourths were sometimes considered problematic, and written around with ornaments or other modifications to the Fauxbourdon style. An example of this is the start of the Marian-Antiphon Ave Maris Stella ( Loudspeaker.svg Listen) by Guillaume Dufay, a master of Fauxbourdon.

Renaissance and Baroque

The development of tonality continued through the Renaissance until it was fully realized by composers of the Baroque era.

Conventional closing cadences Renaissance Kadenz for wikipedia.png
Conventional closing cadences

As time progressed through the late Renaissance and early Baroque, the fourth became more understood as an interval that needed resolution. Increasingly the harmonies of fifths and fourths yielded to uses of thirds and sixths. In the example, cadence forms from works by Orlando di Lasso and Palestrina show the fourth being resolved as a suspension. ( Loudspeaker.svg Listen)

In the early Baroque music of Claudio Monteverdi and Girolamo Frescobaldi triadic harmony was thoroughly utilized. Diatonic and chromatic passages strongly outlining the interval of a fourth appear in the lamento genre, and often in passus duriusculus passages of chromatic descent. In the madrigals of Claudio Monteverdi and Carlo Gesualdo the intensive interpretation of the text (word painting) frequently highlights the shape of a fourth as an extremely delayed resolution of a fourth suspension. Also, in Frescobaldi's Chromatic Toccata of 1635 the outlined fourths overlap, bisecting various church modes.

In the first third of the 18th century, ground-laying theoretical treatises on composition and harmony were written. Jean-Philippe Rameau completed his treatise Le Traité de l'harmonie réduite à ses principes naturels (the theory of harmony reduced to its natural principles) in 1722 which supplemented his work of four years earlier, Nouveau Système de musique theoretique (new system of music theory); these together may be considered the cornerstone of modern music theory relating to consonance and harmony. The Austrian composer Johann Fux published in 1725 his powerful treatise on the composition of counterpoint in the style of Palestrina under the title Gradus ad Parnassum (The Steps to Parnassus). He outlined various types of counterpoint (e.g., note against note), and suggested a careful application of the fourth so as to avoid dissonance.

Classical and romantic

The blossoming of tonality and the establishment of well temperament in Bach's time both had a continuing influence up to the late romantic period, and the tendencies towards quartal harmony were somewhat suppressed. An increasingly refined cadence, and triadic harmony defined the musical work of this era. Counterpoint was simplified to favour an upper line with a clear accompanying harmony. Still, there are many examples of dense counterpoint utilizing fourths in this style, commonly as part of the background urging the harmonic expression in a passage along to a climax. Mozart in his so-called Dissonance Quartet KV 465 ( Loudspeaker.svg Listen) used chromatic and whole tone scales to outline fourths, and the subject of the fugue in the third movement of Beethoven's Piano sonata op. 110 ( Loudspeaker.svg Listen) opens with three ascending fourths. These are all melodic examples, however, and the underlying harmony is built on thirds.

Composers started to reassess the quality of the fourth as a consonance rather than a dissonance. This would later influence the development of quartal and quintal harmony.

The Tristan chord is made up of the notes F, B, D and G and is the first chord heard in Richard Wagner's opera Tristan und Isolde .

Perfect fourth

The chord had been found in earlier works, notably Beethoven's Piano Sonata No. 18, but Wagner's usage was significant, first because it is seen as moving away from traditional tonal harmony and even towards atonality, and second because with this chord Wagner actually provoked the sound or structure of musical harmony to become more predominant than its function, a notion which was soon after to be explored by Debussy and others.

Measures 24 to 27 from Mussorgsky's The Hut on Fowl's Legs Baby Yaga for wikipedia.png
Measures 24 to 27 from Mussorgsky's The Hut on Fowl's Legs

Fourth-based harmony became important in the work of Slavic and Scandinavian composers such as Modest Mussorgsky, Leoš Janáček, and Jean Sibelius. These composers used this harmony in a pungent, uncovered, almost archaic way, often incorporating the folk music of their particular homelands. Sibelius' Piano Sonata in F-Major op. 12 of 1893 used tremolo passages of near-quartal harmony in a way that was relatively difficult and modern. Even in the example from Mussorgsky's piano-cycle Pictures at an Exhibition (Избушка на курьих ножках (Баба-Яга) – The Hut on Fowl's Legs) ( Loudspeaker.svg Listen) the fourth always makes an "unvarnished" entrance.

The romantic composers Frédéric Chopin and Franz Liszt, had used the special "thinned out" sound of fourth-chord in late works for piano ( Nuages gris (Grey Clouds), La lugubre gondola (The Mournful Gondola), and other works).

In the 1897 work The Sorcerer's Apprentice (L'Apprenti sorcier) by Paul Dukas, the repetition of rising fourths is a musical representation of the tireless work of out-of-control walking brooms causes the water level in the house to "rise and rise". Quartal harmony in Ravel's Sonatine and Ma Mère l'Oye (Mother Goose) would follow a few years later.

20th century music

Western classical music

Quartal harmony in "Laideronnette" from Ravel's Ma Mere l'Oye. The top line uses the pentatonic scale
Play (help*info) Ravel Ma Mere l'Oye Laideronnette.PNG
Quartal harmony in "Laideronnette" from Ravel's Ma Mère l'Oye. The top line uses the pentatonic scale Loudspeaker.svg Play  

In the 20th century, harmony explicitly built on fourths and fifths became important. This became known as quartal harmony for chords based on fourths and quintal harmony for chords based on fifths. In the music of composers of early 20th century France, fourth chords became consolidated with ninth chords, the whole tone scale, the pentatonic scale, and polytonality as part of their language, and quartal harmony became an important means of expression in music by Debussy, Maurice Ravel, and others. Examples are found in Debussy's orchestral work La Mer (The Sea) and in his piano works, in particular La cathédrale engloutie (The Sunken Cathedral) from his Préludes for piano, Pour les quartes (For Fourths) and Pour les arpéges composées (For Composite Arpeggios) from his Etudes .

Bartok's music, such as the String Quartet No. 2, often makes use of a three-note basic cell, a perfect fourth associated with an external (C, F, G) or internal (C, E, F) minor second, as a common intervallic source in place of triadic harmonies. Bartok's fourths.png
Bartók's music, such as the String Quartet No. 2, often makes use of a three-note basic cell, a perfect fourth associated with an external (C, F, G) or internal (C, E, F) minor second, as a common intervallic source in place of triadic harmonies.
During Schoenberg's middle period he favoured a chord composed of two fourths, one perfect and one augmented (C, F, B or C, F#, B). Schoenberg's fourths.png
During Schoenberg's middle period he favoured a chord composed of two fourths, one perfect and one augmented (C, F, B or C, F, B).
Quartal chord from Schoenberg's String Quartet No. 1 Schoenberg string quartet quartal chord.png
Quartal chord from Schoenberg's String Quartet No. 1


Jazz uses quartal harmonies (usually called voicing in fourths).

Cadences are often "altered" to include unresolved suspended chords which include a fourth above the bass:

Listen) The II-V-I cadence (
Listen) The fourth-suspension or "sus"-chord II V I for wikipedia.png
( Loudspeaker.svg Listen) The II-V-I cadence ( Loudspeaker.svg Listen) The fourth-suspension or "sus"-chord
Fourths in Herbie Hancock's Maiden Voyage Maiden Voyage2.png
Fourths in Herbie Hancock's Maiden Voyage
Listen The brass section of Ray Barretto's version of Amor Artificial Barretto Amor Artificial.png
Loudspeaker.svg Listen The brass section of Ray Barretto's version of Amor Artificial
Listen Guitar break from Milton Nascimentos composition "Vera Cruz" Nascimento Vera Cruz.png
Loudspeaker.svg Listen Guitar break from Milton Nascimentos composition "Vera Cruz"

See also

Related Research Articles

In music theory, the term minor scale refers to three scale patterns – the natural minor scale, the harmonic minor scale, and the melodic minor scale – rather than just one as with the major scale.

Harmony aspect of music

In music, harmony considers the process by which the composition of individual sounds, or superpositions of sounds, is analysed by hearing. Usually, this means simultaneously occurring frequencies, pitches, or chords.

In music theory, the tritone is defined as a musical interval composed of three adjacent whole tones. For instance, the interval from F up to the B above it is a tritone as it can be decomposed into the three adjacent whole tones F–G, G–A, and A–B. According to this definition, within a diatonic scale there is only one tritone for each octave. For instance, the above-mentioned interval F–B is the only tritone formed from the notes of the C major scale. A tritone is also commonly defined as an interval spanning six semitones. According to this definition, a diatonic scale contains two tritones for each octave. For instance, the above-mentioned C major scale contains the tritones F–B and B–F. In twelve-equal temperament, the tritone divides the octave exactly in half.

A seventh chord is a chord consisting of a triad plus a note forming an interval of a seventh above the chord's root. When not otherwise specified, a "seventh chord" usually means a dominant seventh chord: a major triad together with a minor seventh. However, a variety of sevenths may be added to a variety of triads, resulting in many different types of seventh chords.

Limit (music) mathematical characterization of the harmonic complexity of music; way of characterizing the harmony found in a piece or genre of music, or the harmonies that can be made using a particular scale

In music theory, limit or harmonic limit is a way of characterizing the harmony found in a piece or genre of music, or the harmonies that can be made using a particular scale. The term limit was introduced by Harry Partch, who used it to give an upper bound on the complexity of harmony; hence the name.

Semitone musical interval

A semitone, also called a half step or a half tone, is the smallest musical interval commonly used in Western tonal music, and it is considered the most dissonant when sounded harmonically. It is defined as the interval between two adjacent notes in a 12-tone scale. For example, C is adjacent to C; the interval between them is a semitone.

Major sixth musical interval

In music from Western culture, a sixth is a musical interval encompassing six note letter names or staff positions, and the major sixth is one of two commonly occurring sixths. It is qualified as major because it is the larger of the two. The major sixth spans nine semitones. Its smaller counterpart, the minor sixth, spans eight semitones. For example, the interval from C up to the nearest A is a major sixth. It is a sixth because it encompasses six note letter names and six staff positions. It is a major sixth, not a minor sixth, because the note A lies nine semitones above C. Diminished and augmented sixths span the same number of note letter names and staff positions, but consist of a different number of semitones.

Minor sixth musical interval

In classical music from Western culture, a sixth is a musical interval encompassing six staff positions, and the minor sixth is one of two commonly occurring sixths. It is qualified as minor because it is the smaller of the two: the minor sixth spans eight semitones, the major sixth nine. For example, the interval from A to F is a minor sixth, as the note F lies eight semitones above A, and there are six staff positions from A to F. Diminished and augmented sixths span the same number of staff positions, but consist of a different number of semitones.

In music, quartal harmony is the building of harmonic structures built from the intervals of the perfect fourth, the augmented fourth and the diminished fourth. For instance, a three-note quartal chord on C can be built by stacking perfect fourths, C–F–B.

Guitar chord

In music, a guitar chord is a set of notes played on a guitar. A chord's notes are often played simultaneously, but they can be played sequentially in an arpeggio. The implementation of guitar chords depends on the guitar tuning. Most guitars used in popular music have six strings with the "standard" tuning of the Spanish classical guitar, namely E-A-D-G-B-E' ; in standard tuning, the intervals present among adjacent strings are perfect fourths except for the major third (G,B). Standard tuning requires four chord-shapes for the major triads.

Consecutive fifths

In music, consecutive fifths, or parallel fifths, are progressions in which the interval of a perfect fifth is followed by a different perfect fifth between the same two musical parts : for example, from C to D in one part along with G to A in a higher part. Octave displacement is irrelevant to this aspect of musical grammar; for example, parallel twelfths are equivalent to parallel fifths.

Consonance and dissonance categorizations of simultaneous or successive sounds

In music, consonance and dissonance are categorizations of simultaneous or successive sounds. Consonance is associated with sweetness, pleasantness, and acceptability; dissonance is associated with harshness, unpleasantness, or unacceptability.

Music and mathematics

Music theory has no axiomatic foundation in modern mathematics, yet the basis of musical sound can be described mathematically and exhibits "a remarkable array of number properties". Elements of music such as its form, rhythm and metre, the pitches of its notes and the tempo of its pulse can be related to the measurement of time and frequency, offering ready analogies in geometry.

Dynamic tonality is tonal music which uses real-time changes in tuning and timbre to perform new musical effects such as polyphonic tuning bends, new chord progressions, and temperament modulations, with the option of consonance. The performance of dynamic tonality requires an isomorphic keyboard driving a music synthesizer which implements dynamic tuning and dynamic timbres. Dynamic tonality was discovered by Andrew Milne, William Sethares, and Jim Plamondon.

Post-tonal music theory is the set of theories put forward to describe music written outside of, or 'after', the tonal system of the common practice period. It revolves around the idea of 'emancipating dissonance', that is, freeing the structure of music from the familiar harmonic patterns that are derived from natural overtones. As music becomes more complex, dissonance becomes indistinguishable from consonance.


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