Off Book The point during rehearsals at which actors have memorized their lines and no longer must read from the script.
Off-Broadway Term used to describe theatres and playhouses in New York City not located on or near Broadway in the maintstream theatre. Such playhouses came into being during the 1950's as a result of the high cost of production on Broadway.
Offstage Areas of the stage that are not part of the set.
Old Comedy Refers to the comedies of Aristophanes in ancient Greek Theatre. Old Comedy employed more broadly satirical and topical subject matter than its successors, Middle and New Comedy. It was highly political -- making fun of Athenian society and public figures of the time. Old Comedy, which may have derived from and was certainly influenced by earlier pastoral rites contained much physical comedy of a slap-stick nature, as well as scurrilous jesting and ribaldry.
Oleo Also called a "roll curtain", because it rolls up and down rather than being flown. Used extensively in vaudeville theatre and musical revues, it was often located downstage so that action could take place in front of it while scene or set changes could be accomplished behind it.
Open Stage A platform stage surrounded on three sides by the audience. Derives from the thrust stage of the Elizabethan theatre.
Orchestra From the Greek word for "a dancing place". In ancient times was applied to the circular area where the chorus performed. In Roman theatres, it was the semi-circular area in front of the stage reserved for senators and other important persons. Towards the end of the 17th Century, the term was derived to describe the area in front of the stage where the musicians sat and, ultimately, the term came to refer to the musicians themselves. It is still used to describe the main ground floor seating area in modern theatres.
Orchestra Pit In modern theatres, the sunken area immediately in front of the stage, designed to accomodate musicians.