orchestra

1. (music) A large group of musicians who play together on various instruments, usually including some from strings, woodwind, brass and/or percussion; the instruments played by such a group.Examples: "The orchestra plays music for the dancers to dance to in the 19th century-styled dance hall."; "It requires quite an orchestra to get a train to start; the guard blows his horn, the stationmaster rings a large bell, and the engine whistles."; "Musicians play their instruments. I play the orchestra."

2. (Ancient Greece, theater) A semicircular space in front of the stage used by the chorus in Ancient Greek and Hellenistic theatres.