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 can give a different note for each chord of the music. The four main voices are typically labelled as

soprano A soprano () is a type of classical female singing voice and has the highest vocal range of all voice types. The soprano's vocal range (using scientific pitch notation) is from approximately middle C (C4) = 261 Hz to "high A" (A5) = 880&n ...

(or treble and countertenor),

alto The musical term alto, meaning "high" in Italian (Latin: ''altus''), historically refers to the contrapuntal part higher than the tenor and its associated vocal range. In 4-part voice leading alto is the second-highest part, sung in choruses by ...

(

contralto A contralto () is a type of classical female singing voice whose vocal range is the lowest female voice type. The contralto's vocal range is fairly rare; similar to the mezzo-soprano, and almost identical to that of a countertenor, typica ...

, countertenor or mezzo),

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 is wide ...

, and bass. 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 The Baroque (, ; ) is a style of architecture, music, dance, painting, sculpture, poetry, and other arts that flourished in Europe from the early 17th century until the 1750s. In the territories of the Spanish and Portuguese empires including th ...

, a set of rules developed for

voice leading Voice leading (or part writing) is the linear progression of individual melodic lines ( voices or parts) and their interaction with one another to create harmonies, typically in accordance with the principles of common-practice harmony and counte ...

in four-part harmony. In these rules, the bass voice would be assigned the

root In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the su ...

of the chord, although it can occasionally be assigned the fifth or the third. If the chord is a triad, the root is generally doubled by one of the other voices. When two voices are harmonized in

perfect interval In music theory, an interval is a 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 h ...

s (fourths, fifths and octaves), repeats of the same interval between the two voices (also known as moving in

parallel Parallel is a geometric term of location which may refer to: Computing * Parallel algorithm * Parallel computing * Parallel metaheuristic * Parallel (software), a UNIX utility for running programs in parallel * Parallel Sysplex, a cluster of ...

s) are almost always avoided. Another rule concerns

perfect cadence In Western musical theory, a cadence (Latin ''cadentia'', "a falling") is the end of a phrase in which the melody or harmony creates a sense of full or partial resolution, especially in music of the 16th century onwards.Don Michael Randel (1999 ...

s. In such cadences, the

leading tone In music theory, a leading-tone (also called a subsemitone, and a leading-note in the UK) is a note or pitch which resolves or "leads" to a note one semitone higher or lower, being a lower and upper leading-tone, respectively. Typically, ''the ...

(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 mathematics ...

) 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 characte ...

. 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