in Music. See the article Music. ORCHESTRA, in the Grecian theatres, was that part of the prosenium or stage where the chorus used to dance. In the middle of it was placed the dais or pulpit. The orchestra was semicircular, and surrounded with seats. In the Roman theatres it formed no part of the scene, but answered pretty nearly to the pit in our playhouses, being occupied with seats for senators, magistrates, vestals, and other persons of distinction. The actors never went down into the orchestra.