The word "orchestra" was used to describe the place where musicians and dancers performed in ancient Greece. The orchestra, or symphony orchestra, is generally defined as an ensemble mainly composing of bowed stringed instruments, percussion, wind and brass instruments. Often, the orchestra is composed of 100 musicians and may be accompanied by a chorus or be purely instrumental. In today's setting, the word "orchestra" not only pertains to a group of musicians but also to the main floor of a theater.