Why Is it Bad Luck To Whistle Backstage In a Theatre and Where Did the Superstition Come From?

Whistling backstage became bad luck during a time in England when stagehands were most often sailors without a ship.

The curtain, flies, and props were moved manually by a system of ropes, so the sailors communicated as they did at sea, by whistling.

If someone not involved in the intricate backstage maneuvers were to whistle, a stagehand might take it as a cue, which could be disastrous for the production.