A body of singers who perform together is called a choir or chorus. The former term is very often applied to groups affiliated with a church (whether or not they actually occupy the choir) and the second to groups that perform in theatres or concert halls, but this distinction is far from rigid. "Choir" has the secondary definition of a subset of an ensemble; thus one speaks of the "woodwind choir" of an orchestra, or different "choirs" of voices and/or instruments in a polychoral composition. In typical 18th to 20th century oratorios and masses, chorus or choir is usually understood to imply more than one singer per part, in contrast to the quartet of soloists also featured in these works.
Choirs can sing with or without instrumental accompaniment. Singing without accompaniment is called a cappella singing (although the American Choral Directors Association discourages this usage in favor of "unaccompanied," since "a cappella" denotes singing "as in the chapel" and much unaccompanied music today is secular). Accompanying instruments can consist of practically any instruments, from one to a full orchestra; for rehearsals a piano or organ accompaniment is often used even if a different instrumentation is planned for performance, or for rehearsing a cappella music. While Eastern Orthodox churches and some synagogues ban the use of instruments, in churches of the Western Rite the accompanying instrument is almost always an organ, although in colonial America, the Moravian Church used a string quartet. Many churches which use a contemporary worship format will have a band in the sanctuary to accompany the singing.
Beside the leading of singing in which the congregation participates such as hymns and service music, choirs still sing the full propers (introit, gradual, communion antiphons appropriate for the different times of the liturgical year) at a few churches, chiefly those of the Anglican or Roman Catholic churches; far more common however is the performance of an anthem at the offertory. Roman Catholic Churches use, at their discretion, additional orchestral accompaniment. The most noted Roman Catholic Church in the world to use an orchestral accompaniment is Saint Patrick's Cathedral in New York City.
Choirs can be categorized by the voices they include:
Choirs are also categorized by the institutions in which they operate:
Finally, some choirs are categorized by the type of music they perform, such as
There are various schools of thought regarding how the various sections should be arranged on stage. In symphonic choirs it is common (though by no means universal) to order the choir behind the orchestra from highest to lowest voices from left to right, corresponding to the typical string layout. In Germany the conductor Helmut Kickton introduced 2000 the historic layout of the 17th –19th century with the choir in front of the orchestra. In a cappella or piano-accompanied situations it is not unusual for the men to be in the back and the women in front; some conductors prefer to place the basses behind the sopranos, arguing that the outer voices need to tune to each other.
More experienced choirs often sing with the voices all mixed together. Proponents of this method argue that it makes it easier for each individual singer to hear and tune to the other parts, but it requires more independence from each singer. Opponents argue that this method loses the spatial separation of individual voice lines, an otherwise valuable feature for the audience, and that it eliminates sectional resonance, which lessens the effective volume of the chorus.
For music with double (or multiple) choirs, usually the members of each choir are together, sometimes significantly separated, especially in performances of 16th-century music. Some composers actually specify that choirs should be separated, such as in Benjamin Britten's War Requiem.
Consideration is also given to the spacing of the singers. Studies have found that not only the actual formation, but the amount of space (both laterally and circumambiently) affect the perception of sound by choristers and auditors.
Singers who have perfect pitch require yet other skills:
The earliest notated music of western Europe is Gregorian Chant, along with a few other types of chant which were later subsumed (or sometimes suppressed) by the Catholic Church. This tradition of unison choir singing lasted from sometime between the times of St. Ambrose (4th century) and Gregory the Great (6th century) up to the present. During the later Middle Ages, a new type of singing involving multiple melodic parts, called organum, became predominant for certain functions, but initially this polyphony was only sung by soloists. Further developments of this technique included clausulae, conductus and the motet (most notably the isorhythmic motet), which, unlike the Renaissance motet, describes a composition with different texts sung simultaneously in different voices. The first evidence of polyphony with more than one singer per part comes in the Old Hall Manuscript (1420, though containing music from the late 1300s), in which there is occasional divisi (where one part divides into two different notes, something a solo singer obviously couldn't handle).
During the Renaissance, sacred choral music was the principal type of (formal or 'serious') music in Western Europe. Throughout the era, hundreds of masses and motets (as well as various other forms) were composed for a cappella choir, though there is some dispute over the role of instruments during certain periods and in certain areas. Some of the better-known composers of this time include Dufay, Josquin des Prez, Giovanni Pierluigi da Palestrina, and William Byrd; the glories of Renaissance polyphony were choral, sung by choirs of great skill and distinction all over Europe. Choral music from this period continues to be popular with many choirs throughout the world today.
Madrigals are another particularly popular form dating from this period. Although madrigals were initially dramatic settings of unrequited-love poetry or mythological stories in Italy, they were imported into England and merged with the more upbeat balletto, celebrating often silly songs of spring, or eating and drinking. To most English speakers, the word madrigal now refers to the latter, rather than to madrigals proper, which refers to a poetic form of lines consisting of seven and eleven syllables each.
The interaction of sung voices in Renaissance polyphony influenced Western music for centuries. Composers are routinely trained in the "Palestrina style" to this day, especially as codified by the 18c music theorist Johann Joseph Fux. Composers of the early twentieth century also endeavored to extend and develop the Renaissance styles. Herbert Howells wrote a Mass in the Dorian mode entirely in strict Renaissance style, and Ralph Vaughan Williams's Mass in G minor is an extension of this style. Anton von Webern wrote his dissertation on the Choralis Constantinus of Heinrich Isaac and the contrapuntal techniques of his serial music seems informed by this study.
A new choral style was the vocal concertato, combining voices and instruments; its origins may be sought in the polychoral music of the Venetian school. Claudio Monteverdi (1567-1643) brought it to perfection with his Vespers and his Eighth Book of Madrigals, which call for great virtuosity on the part of singers and instruments alike. His pupil Heinrich Schütz (1585-1672) (who had earlier studied with Giovanni Gabrieli) introduced the new style to Germany. Alongside the new music of the secunda prattica, contrapuntal motets in the stilo antico or old style continued to be written well into the 19th century.
It should be remembered that choirs at this time were usually quite small and that singers could be classified as suited to church or to chamber singing. Monteverdi, himself a singer, is documented as taking part in performances of his Magnificat with one voice per part.
Independent instrumental accompaniment opened up new possibilities for choral music. Verse anthems alternated accompanied solos with choral sections; the best-known composers of this genre were Orlando Gibbons and Henry Purcell. Grand motets (such as those of Lully and Delalande) separated these sections into separate movements. Oratorio, pioneered by Giacomo Carissimi, extended this concept into concert-length works, usually loosely based on Biblical stories.
The pinnacle of the oratorio is found in George Frideric Handel's works, notably Messiah and Israel in Egypt. While the modern chorus of hundreds had to await the growth of Choral societies and his centennial commemoration concert, we find Handel already using a variety of performing forces, from the soloists of the Chandos Anthems to larger groups (whose proportions are still quite different from modern orchestra choruses):
Lutheran composers wrote instrumentally-accompanied cantatas, often based on chorales (hymns). While Dieterich Buxtehude was a significant composer of such works, it was largely up to the next generation to undertake cantata cycles on texts for the entire church year. Telemann wrote choral cantatas for Frankfurt (later published in solo versions as the Harmonische Gottesdienst), but Johann Sebastian Bach (1685-1750) made a truly monumental contribution: his obituary mentions five complete cycles, of which three comprising some 200 works are known today, in addition to motets, (Bach himself did not use the term "cantata", motet here refers to his "church music" without orchestra) passions, masses and the Magnificat.
A point of hot controversy today is the so-called "Rifkin hypothesis", which re-examines the famous "Entwurff", Bach's 1730 memo to the Leipzig City Council (A Short but Most Necessary Draft for a Well Appointed Church Music) calling for at least 12 singers. In light of Bach's responsibility to provide music to four churches and be able to perform double choir compositions with a substitute for each voice, Joshua Rifkin concludes that Bach's music was written with one voice per part in mind, though this point is highly contested within the Historically Informed Practice movement and elsewhere.
In the 19th century, sacred music escaped from the church and leaped onto the concert stage, with large sacred works unsuitable for church use, such as Berlioz's Te Deum and Requiem, and Brahms's Ein deutsches Requiem. Rossini's Stabat mater, Schubert's masses, and Verdi's Requiem also exploited the grandeur offered by instrumental accompaniment.
Oratorios also continued to be written, clearly influenced by Handel's models. Berlioz's L'Enfance du Christ and Mendelssohn's Elijah and St Paul are in the category. Schubert, Mendelssohn, and Brahms also wrote secular cantatas, the best known of which are Brahms's Schicksalslied and Nänie.
A few composers developed a cappella music, especially Bruckner, whose masses and motets startlingly juxtapose Renaissance counterpoint with chromatic harmony. Mendelssohn and Brahms also wrote significant a cappella motets.
The amateur chorus (beginning chiefly as a social outlet) began to receive serious consideration as a compositional venue for the part-songs of Schubert, Schumann, Mendelssohn, Brahms, and others. These 'singing clubs' were often for women or men separately, and the music was typically in four-part (hence the name "part-song") and either a cappella or with simple instrumentation. At the same time, the Cecilian movement attempted a restoration of the pure Renaissance style in Catholic churches.
The late-Romantic composers, such as Richard Strauss and Sergei Rachmaninoff, contributed to the genre. Ralph Vaughan Williams's Mass in G minor harks back to the Renaissance style while exhibiting the vibrancy of new harmonic languages. Vaughan Williams also arranged English and Scottish folk songs. Arnold Schoenberg's Friede auf Erden is a tonal kaleidoscope, whose tonal centers are constantly shifting (his harmonically innovative Verklärte Nacht for strings dates from the same period).
At the end of the 19th century and the start of the twentieth, male voice choirs became popular with the coal miners of South Wales, and numerous choirs were established including the Treorchy Male Choir, Morriston Orpheus Choir and Cor Meibion Pontypridd Male voice choirs. Although the mining communities which gave rise to these choirs largely died out in the 1970s and 1980s with the decline of the Welsh coal industry, many of these choirs continue, and are seen as a traditional part of Welsh culture and perform Worldwide.
The advent of atonality and other non-traditional harmonic systems and techniques in the 20th century also affected choral music. Serial music is represented by choral works by Arnold Schoenberg, including the anthem "Dreimal Tausend Jahre," while the composer's signature use of sprechstimme is evident in his psalm "De Profundis." Paul Hindemith's distinctive modal language is represented by both his a cappella Mass and his Six Chansons on texts by Rilke, while a more contrapuntally dissonant style comes through in his secular requiem, When Lilacs Last in the Dooryard Bloom'd. Olivier Messiaen also demonstrates dissonant counterpoint in his Cinq Rechants, which tell the Tristan and Isolde story. Charles Ives' psalm settings exemplify the composer's incomparably radical harmonic language. Tone clusters and aleatory elements play a prominent role in the choral music of Krzysztof Penderecki, who wrote the St. Luke Passio, and Gyorgy Ligeti, who wrote both a Requiem and a separate Lux Aeterna. Milton Babbitt incorporated integral serialism into works for children's chorus, while Daniel Pinkham wrote for choir and electronic tape. Meredith Monk's Panda Chant and Astronaut Anthem explore overtones in an unconventional text setting. Though difficult and rarely performed by amateurs, pieces that demonstrate such unfamiliar idioms have found their way into the repertories of the finest semi-professional and professional choirs around the world.
More accessible styles of choral music include that by Benjamin Britten, including his War Requiem, Five Flower Songs, and Rejoice in the Lamb. Francis Poulenc's Motets pour le temps de noël, Gloria, and Mass in G are often performed. A primitivist approach is exemplified by Carl Orff's widely performed Carmina Burana. In the United States, Aaron Copland, Samuel Barber, and Randall Thompson wrote signature American pieces. In Eastern Europe, Béla Bartók and Zoltán Kodály wrote a small amount of music for choirs. Frank Martin's Mass for double choir combines modality and allusion to Medieval and Renaissance forms with a distinctly modern harmonic language and has become the composer's most performed work.
Sacred Minimalism is represented by Arvo Pärt, whose Johannespassion and Magnificat have received regular performances; The music of John Tavener (Song for Athene) and Henryk Gorecki (Totus Tuus) also receives frequent playings within this genre. American minimalism and post minimalism are represented by Steve Reich's Desert Music, choral excerpts from Philip Glass's Einstein on the Beach and John Adams' The Death of Klinghoffer, and David Lang's Pulitzer Prize-winning Little Match Girl Passion.
Black Spirituals came into greater prominence and arrangements of such spirituals became part of the standard choral repertoire. Notable composers and arrangers of choral music in this tradition include William Dawson, Jester Hairston and Moses Hogan.
During the mid 20th century, barbershop quartets began experimenting with combining larger ensembles together into choruses which sing barbershop music in 4 parts, often with staging, choreography and costumes. The first international barbershop chorus contest was held in 1953 and continues to this day.
During the late 20th century, one of the major areas of growth in the choral movement has been in the areas of LGBT choruses. Starting around 1979, gay men's choruses were founded within a period of months in major U.S. cities such as New York, Los Angeles, Seattle and Dallas. Over the last quarter century the number of such groups, men's, women's and mixed, has exploded. GALA Choruses, an associative group, now has well-over 100 member choruses throughout the world.
At the turn of the 21st century, choral music has received a resurgence of interest partly due to a renewed interest in accessible choral idioms. Multi-cultural influences are found in Osvaldo Golijov's St. Mark Passion, which melds the Bach-style passion form with Latin American street music, and Chen Yi's Chinese Myths Cantata melds atonal idioms with traditional Chinese melodies played on traditional Chinese instruments. Some composers began to earn their reputation based first and foremost on their choral output, with the highly popular John Rutter, Morten Lauridsen, and Eric Whitacre being three of the most well-known examples. The large scale dramatic works of Karl Jenkins seem to hearken back to the theatricality of Orff, and the music of James MacMillan continues the tradition of boundary-pushing choral works from the United Kingdom begun by Britten, Walton, and Leighton. Meanwhile, primarily media music composers such as John Williams and Kentaro Sato, and prominent concert orchestral composers such as Augusta Read Thomas, Sofia Gubaidulina, Aaron Jay Kernis, and Thomas Ades also contribute vital additions to the choral repertoire.