Four-part harmony is music written for four voices, or for some other musical medium—four

musical instrument A musical instrument is a device created or adapted to make Music, musical sounds. In principle, any object that produces sound can be considered a musical instrument—it is through purpose that the object becomes a musical instrument. A person ...

s 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 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 Hertz, Hz to A5 in Choir, choral ...

(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 four-part voice leading alto is the second-highest part, sung in ch ...

(

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

countertenor A countertenor (also contra tenor) is a type of classical male singing voice whose vocal range is equivalent to that of the female contralto or mezzo-soprano voice types, generally extending from around G3 to D5 or E5, although a sopranist (a ...

or mezzo),

tenor A tenor is a type of male singing voice whose vocal range lies between the countertenor and baritone voice types. It is the highest male chest voice type. Composers typically write music for this voice in the range from the second B below m ...

, 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, 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 cou ...

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

root In vascular plants, the roots are the plant organ, 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 bel ...

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 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) 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 ( , , ; ; ) is the most acceptable and comfortable vocal range for a given singer (or, less frequently, musical instrument). It is the range in which a given type of voice presents its best-sounding (or characteristic) tim ...

. 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