sentences:  The seating may also be specified by the composer, as in Béla Bartók's "Music for Strings, Percussion and Celesta", which uses antiphonal string sections, one on each side of the stage.In some cases, due to space constraints (as with an opera pit orchestra) or other issues, a different layout may be used.In a typical stage set-up, the first and second violins, violas and cellos are seated by twos, a pair of performers sharing a stand being called a "desk", Each principal (or section leader) is usually on the "outside" of the first desk, that is, closest to the audience.