Perfect fourth
Inverse | perfect fifth |
---|---|
Name | |
Other names | diatessaron |
Abbreviation | P4 |
Size | |
Semitones | 5 |
Interval class | 5 |
Just interval | 4:3 |
Cents | |
12-Tone equal temperament | 500 |
Just intonation | 498 |
A fourth is a
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.
A perfect fourth in just intonation corresponds to a pitch ratio of 4:3, or about 498 cents (ⓘ), while in equal temperament a perfect fourth is equal to five semitones, or 500 cents (see additive synthesis).
Until the late 19th century, the perfect fourth was often called by its Greek name, diatessaron.
An example of a perfect fourth is the beginning of the "Bridal Chorus" from
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 occurs "above the bass in chords with three or more notes".[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.
Conventionally, adjacent strings of the
History
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.
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:
- In the earliest stages, these simple intervals occur so frequently that they appear to be the favourite sound of composers.
- Later, the more "complex" intervals (thirds, sixths, and tritones) move gradually from the margins to the centre of musical interest.
- By the end of the Middle Ages, new rules for voice leading had been laid, re-evaluating the importance of unison, octave, fifth and fourth and handling them in a more restricted fashion (for instance, the later forbidding of parallel octaves and fifths).
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
For instance, in one "Alleluia" (
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-
Renaissance and Baroque
The development of tonality continued through the Renaissance until it was fully realized by composers of the Baroque era.
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
)In the early Baroque music of
In the first third of the 18th century, ground-laying theoretical treatises on composition and
Classical and romantic
The blossoming of tonality and the establishment of
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.
The chord had been found in earlier works, notably
Fourth-based harmony became important in the work of Slavic and Scandinavian composers such as
The romantic composers
In the 1897 work
20th century music
Western classical music
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
Jazz
Jazz uses quartal harmonies (usually called voicing in fourths).
See also
- All fifths
- Lists of intervals
- List of meantone intervals
- Eleventh
References
- ISBN 9780790582290.
- ^ Sean Ferguson and Richard Parncutt. "Composing in the Flesh: Perceptually-Informed Harmonic Syntax" (PDF). Archived from the original (PDF) on 2005-10-13. Retrieved 2006-09-05.
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(help) - ^ Paul, Oscar (1885). A manual of harmony for use in music-schools and seminaries and for self-instruction, p.165. Theodore Baker, trans. G. Schirmer.
- John Tyrrell(London: Macmilln Publishers).
- ISBN 978-0-07-294262-0.
- ISBN 978-0-393-95272-8.
- ^ Morgan (1991), p. 71. "no doubt for its 'nontonal' quality"
- ^ Floirat, Bernard (2015). "Introduction aux accords de quartes chez Arnold Schoenberg". p. 19 – via https://www.academia.edu/.
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