The word “ensemble” comes from the French meaning “together” and is a broad concept that encompasses groupings of various constituencies and sizes. Ensembles can be made up of singers alone, instruments alone, singers and instruments together, two performers or hundreds. Ensemble performance is part of virtually every musical tradition. Examples of large ensembles are the symphony orchestra, marching band, jazz band, West Indian steel pan orchestra, Indonesia gamelan, African drum ensembles, chorus, and gospel choir. In such large groups, performers are usually divided into sections, each with its particular material or function. So, for example, all the tenors in a chorus sing the same music, and all the alto saxes in a jazz big band play the same part. Usually a conductor or lead performer is responsible for keeping everyone together.
The large vocal ensemble most familiar to Westerners is the chorus, twenty or more singers grouped in soprano, alto, tenor, and bass sections. The designation choir is sometimes used for choruses that sing religious music. There is also literature for choruses comprised of men only, women only, and children. Small vocal ensembles, in which there are one to three singers per part, include the chamber chorus and barber shop quartet. Vocal ensemble music is sometimes intended to be performed a cappella, that is, by voices alone, and sometimes with instruments. Choral numbers are commonly included in operas, oratorios, and musicals.
The most important large instrumental ensemble in the Western tradition is the symphony orchestra. Orchestras such as the New York Philharmonic, Brooklyn Philharmonic,
and those of the New York City Opera and Metropolitan Opera, consist of 40 or more players, depending on the requirements of the music they are playing. The players are grouped by family into sections – winds, brass, percussion and strings. Instruments from different sections frequently double each other, one instrument playing the same material as another, although perhaps in different octaves. Thus, while a symphony by Mozart may have parts for three sections, the melody given to the first violins is often identical to that of the flutes and clarinets; the bassoons, cellos and basses may join forces in playing the bass line supporting that melody while the second violins, violas, and French horns are responsible for the pitches that fill out the harmony. The term orchestration refers to the process of designating particular musical material to particular instruments.
The origins of the orchestra in Western Europe date back to the early baroque and the rise of opera, for which composers wrote instrumental overtures, accompaniments to vocal numbers, and dances. In this early period, the ensemble typically consisted of about 16 to 20 strings plus a harpsichord, called the continuo, that doubled the bass line and filled out the harmonies. Other instruments could be included, but primarily as soloists rather than regular members. The designation chamber orchestra is sometimes applied to these early orchestras, reflecting the fact that, during the Baroque period, orchestral music was often composed as entertainment for the nobility and performed in the rooms, or chambers, of their palaces, rather than the large concert halls of today.
During the classical period, the orchestra expanded in size to between 40 and 60 players. Strings remain the heart of the ensemble, but there are more of them, and by the early 19th century, pairs of flutes, oboes, clarinets, bassoons, French horns, trumpets and timpani had become standard members. For the most part, the woodwinds double the strings, the horns fill out the harmonies, and the trumpets and timpani add rhythmic emphasis. For many composers of the 19th century, exploring the timbral possibilities of the orchestra became an increasingly important aspect of the creative process. The ensemble of the romantic period grew to 80 or more players through the increase in the numbers of instruments of the classical orchestra and the addition of new ones – piccolo, English horn, contrabassoon, trombone, tuba, harp, celeste, cymbals, triangle, a variety of drums. Scores also called for special effects such as muting – muffling or altering the sound of string instruments by placing a wooden clamp placed across the bridge, or brass instruments by inserting material into the bell. There is no single concept of the orchestra in the 20th century. Composers have written for chamber
ensembles and for gigantic forces; they have used traditional instrumentations but also further extended the palette of musical tone colors by incorporating non-western instruments, invented instruments, electronically altered instruments, and non-musical sound sources such as sirens. Some have approached the orchestra not as the deliverer of melody, rhythm, and harmony, but as a palette of tone colors, to be mixed, juxtaposed, manipulated, ordered, and experienced as a sonic collage.
The jazz big band is another example of a large ensemble. The instruments are typically divided into the reed section (saxes, sometimes clarinets), the brass section (trumpets, trombones, sometimes cornets), and the rhythm section (commonly piano, guitar, string bass, and drum set). The rhythm section – which appears in most groups, large and small – is responsible for maintaining the rhythm (hence the name) as well as the harmony on which the featured soloists are improvising. Because of their size, jazz big bands often play from written arrangements (see Chapter 7: Jazz)
The gamelan of Indonesia is an example of a large non-Western ensemble. The distinctive sound of the gamelan is created by metallophones, that is, instruments made of
metal and struck with a mallet. Some resemble small, medium, and large xylophones, but with tuned bars of bronze instead of wood. Some look like a collection of lidded cooking kettles of different sizes. The layers of melody created by these instruments are punctuated by gongs, chimes, and drums. The gamelan accompanies ceremonial plays and dances and is deeply connected to religious rituals. The instruments themselves are charged with charismatic power and are often intricately carved and brilliantly painted with figures and designs that replicate elements of cosmological forces.
Another type of grouping found in many musical traditions consists of a small number of players – from 2 to 8 or 9 – each of whom has a separate, unique part. An important feature of small ensembles is an overall balance among the individual performers, so that one does not overpower the others. Instead, every member of the group plays an essential role in the presentation and development of musical ideas. Instead of a conductor, the performers rely on eye contact, careful listening and sensitivity to each other that may have developed over years of rehearsing and playing together. In the western classical tradition, such small groups are classified as chamber ensembles and include the string quartet (2 violins, viola, cello), piano trio (piano, violin, cello), and wind quintet (flute, oboe, clarinet, bassoon, French horn). A comparable small group in jazz is a jazz combo. Like the jazz big band, the jazz combo uses a rhythm section, but in place of reed and brass sections, a handful of additional improvising instruments. One referred combination is the jazz quintet, made up of trumpet, saxophone, and rhythm section of piano, bass, and drums. Miles Davis’s famous quintet of the 1960s used this instrumentation. Other examples of small instrumental groupings include a bluegrass band, Klezmer band, rock band, and trio of players of Indian ragas.