Global InformationOffstage instrument or choir part in classical music information
An offstage instrument or choir part in classical music is a sound effect used in orchestral and opera which is created by having one or more instrumentalists (trumpet players, also called an "offstage trumpet call", horn players, woodwind players, percussionists, other instrumentalists) from a symphony orchestra or opera orchestra play a note, melody, or rhythm from behind the stage, or having a choir of singers sing a melody from behind the stage.
This creates a distant, muted effect which composers use to suggest "celestial voices", melancholy, or nostalgia, or to create a haunting or mysterious effect. Some composers use larger offstage groups, (such as the 14 offstage brass instruments in Richard Strauss' Alpine Symphony) that they can create antiphonal effects, in which the main orchestra and the offstage instruments alternate their parts. In some works, the offstage instruments are arrayed in the balconies or amidst the audience, which is a more forceful sound, since the volume is not muted by walls or doors. In some pieces, the offstage performers change how far they are away from the main orchestra in their first and second performance in a piece; if a performer moves from far backstage to close to the wings, it will give the audience the impression that the band is moving closer.
The conductor decides where to position the offstage instruments or singers, whether this is backstage, in the wings, balcony, or elsewhere. When there are large offstage ensembles, they may be conducted by a second assistant conductor. In the 19th century and the early 20th century, prior to the invention of closed circuit television, offstage music was challenging to coordinate with the onstage ensemble, because to achieve the muted, distant effect that is often sought out, the players or singers would have to move fairly far backstage; however, getting far away from the main orchestra made it hard to stay in time and in tune with the main orchestra. Since the 1970s and 1980s, the widespread availability of technologies such as affordable closed circuit TV cameras and TV monitors, monitor speakers, and in the 1980s, inexpensive electronic tuners made it easier to coordinate offstage and onstage musicians and/or singers with the onstage ones.
An offstage part may be requested by the use of the German instruction "auf dem Theater" or the Italian instructions "tromba interna" or "banda". While offstage instrumental parts are usually for brass or percussion instruments, in Berlioz' Symphonie Fantastique, an offstage oboe is used in the third movement and in Krzysztof Penderecki's Symphony No. 7 "Seven Gates of Jerusalem", the brass and percussion are joined by clarinets, bassoons, and a contrabassoon.