Orchestra first named the space in front of a Greek stage kept for the chorus
An orchestra is a large ensemble, classical or jazz, that combines instrument families into one sound: strings, woodwinds, brass and percussion, with harp, keyboards and even electric guitars joining when a score demands. The name comes from the space in front of an ancient Greek stage reserved for the chorus.
Each section has a standard roster. Strings mean violins, violas, cellos and double basses. Woodwinds cover flute, oboe, clarinet and bassoon, sometimes stretched with piccolo, cor anglais, bass clarinet, contrabassoon or saxophone. Brass brings horn, trumpet, trombone and tuba, occasionally cornet and euphonium. Percussion includes timpani, snare and bass drums, cymbals, triangle, tambourine, tam-tam and tuned mallet instruments. The harp is a regular guest, especially in Romantic works, and piano, harpsichord, organ, celesta or accordion may form a keyboard group or appear as soloists.
Size varies with the music. A full symphony or philharmonic orchestra, the latter name built from Greek words for loving and harmony, fields seventy to more than a hundred players depending on the piece and hall, while a chamber orchestra tops out around fifty. Ensembles for Bach, Handel, Haydn and Mozart tend to be leaner than those playing Beethoven or Brahms. Orchestras swelled across the eighteenth and nineteenth centuries, peaking with the forces of up to 120 musicians that Wagner and Mahler demanded.
Baroque practice was far from uniform. Regions differed in instruments, playing style and numbers, from one player per part to big string bands. Bach at Köthen had an ensemble of at most 18, whereas Corelli in Rome directed 35 to 80 players day to day and as many as 150 on grand occasions. In that era, running roughly from 1600 to 1750, the group was often led by the principal violinist or by a keyboard player handling the basso continuo, a custom some early-music groups still follow.
Today a conductor usually takes charge, using hand gestures and often a short baton to set tempo, balance the sound and bind the players together, and running rehearsals to shape interpretation before the concert. The principal first violinist, called the concertmaster in America and the leader in Britain, remains a key figure. Orchestras play symphonies, concertos and overtures and fill the pits for opera, ballet and some musical theatre, such as Gilbert and Sullivan. Youth and community orchestras give amateurs their own stage.
Source: Orchestra
