The term "four-part harmony" refers to music written for four voices, or for some other musical medium—four musical instruments or a single keyboard instrument, for example—for which the various

musical parts A part (or voice) generally refers to a single strand or melody or harmony of music within a larger ensemble or a polyphonic musical composition. There are several senses in which the word is often used: * the physical copy of printed or writte ...

can give a different note for each

chord Chord may refer to: * Chord (music), an aggregate of musical pitches sounded simultaneously ** Guitar chord a chord played on a guitar, which has a particular tuning * Chord (geometry), a line segment joining two points on a curve * Chord ( ...

of the music. The four main voices are typically labelled as soprano (or treble and countertenor), alto ( contralto, countertenor or

mezzo Mezzo is the Italian word for "half", "middle" or "medium". It may refer to: Music *Mezzo-soprano or mezzo, a type of classical female singing voice whose range lies between the soprano and the contralto singing voices *Mezzo forte ("medium-loud") ...

tenor A tenor is a type of classical male singing voice whose vocal range lies between the countertenor and baritone voice types. It is the highest male chest voice type. The tenor's vocal range extends up to C5. The low extreme for tenors i ...

, and

bass Bass or Basses may refer to: Fish * Bass (fish), various saltwater and freshwater species Music * Bass (sound), describing low-frequency sound or one of several instruments in the bass range: ** Bass (instrument), including: ** Acoustic bass gui ...

. Because the human voice has a limited range, different voice types are usually not able to sing pitches that lie outside of their specific range. The effort required to perform four-part harmony varies greatly. Pieces written in such a style can be usually executed by a single keyboard player, a group of 4 instruments (or singers), or even a large choir with multiple singers per part.

In European classical music

In the baroque era, a set of rules developed for voice leading in four-part harmony. In these rules, the bass voice would be assigned the root of the chord, although it can occasionally be assigned the fifth or the third. If the chord is a

triad Triad or triade may refer to: * a group of three Businesses and organisations * Triad (American fraternities), certain historic groupings of seminal college fraternities in North America * Triad (organized crime), a Chinese transnational orga ...

, the root is generally doubled by one of the other voices. When two voices are harmonized in perfect intervals (fourths, fifths and octaves), repeats of the same interval between the two voices (also known as moving in parallels) are almost always avoided. Another rule concerns perfect cadences. In such cadences, the leading tone (the seventh scale

degree Degree may refer to: As a unit of measurement * Degree (angle), a unit of angle measurement ** Degree of geographical latitude ** Degree of geographical longitude * Degree symbol (°), a notation used in science, engineering, and mathemati ...

) must resolve step-wise to the tonic. That is, the voice that plays the leading tone must resolve up to the tonic, and if the chord is a dominant seventh chord, the subdominant should resolve to the mediant. Another concern of four-part writing is

tessitura In music, tessitura (, pl. ''tessiture'', "texture"; ) is the most acceptable and comfortable vocal range for a given singer or less frequently, musical instrument, the range in which a given type of voice presents its best-sounding (or charac ...

. Since the music is usually written for four-part choirs, each part should be able to be sung by the appropriate section of the choir, thus it should remain in the appropriate pitch range. As well as that, each voice should be easy to sing, meaning that large intervals within the same voice are to be avoided, instead favoring step-wise motion. Voices should also not overlap: the pitch sung by the alto should not be higher than that of the soprano, and so on for the other voices. Voices should also remain suitably close to each other, usually within an octave of each adjacent voice, except for the bass. These rules were generally followed during the common practice period. Nowadays, they are usually taught in music theory classes, but most compositions follow less strict rules, if not outright disregarding them.

References

{{Harmony

In European classical music

See also

References