The Superstition: Whistling is expressly prohibited in the theatre, pertaining to all parts of the building, particularly the dressing rooms, where it is said that if heard, someone (not necessarily the whistler) will soon be out of work. The Origin: The reason for this superstition is as follows: before the advent of walkie-talkies or clear-coms, cues for theatre technicians were called with a sailors whistle. Therefore, one who whistles in a theatre may, inadvertantly, call a cue before it's time, setting all types of catastrophy into motion.