The theatre is riddled with hundreds of superstitions from the actor's personal warm-up rituals to the phrase "break a leg." Many come from obscure origins but some have practical applications.
Did you know that the believe that it is bad luck to whistle in a theatre actually has some very practical safety applications?
Back in the day, since sailors were experts with ropes and rigging, they were often hired to help run the fly systems of a theatre. This was also long before the convienience of modern headsets that would allow the stagehands to communicate silently with each other. Instead, the riggers employed a method they learned on the ships: whistling. Whistling would serve as a signal to one another as they flew in flats and counter weights. So if you were happening be whistling as you were walking across the stage, it is conceivable that the riggers in the flies might get confused and bring in an unintentional set piece right on your head.
The superstition is obviously outdated, but it does serve as a good reminder to pay close attention to safety while working in a theatre space. You never know what could be dropped on your head from above.
Happy Birthday: Geoffrey Rush (b. 1951)