This reminds of the time I was active in theatre as an actor. We were doing the musical Calamity Jane and one night when we were all lined up singing Take me back to the black hills, the black hills of Dakota, a very mournful number, the audience burst out laughing. All the men looked down to see if their flies were open. No such thing. Some cack handed stage hand in the wings had brushed against a handle which released very colourful bunting all over the black hills scenery. Happy days.