Sometimes they spend more time onstage than performers. During the show, unseen by the audience, they are busy working behind the scenes. They change the stage floor, set up scenery and rigging for the scene to follow. The Warsaw opera house employs over sixty stagehands, including scenery fitters, upholsters, and running crew who operate stage machinery to move set pieces. It is thnaks to them that performers appear from underneath or fly down on the stage from above.