I remember hearing years ago about some rock star who insisted on a bowl of green M&M's in their dressing room, and threw a fit if it wasn't there. Years later I learned _why_, I think from an Amanda Palmer interview.
Some types of touring musicians drag enormous quantities of elaborate and expensive equipment with them from city to city: maybe a million dollars worth of instruments, lights, amplifiers, mixing boards, pyrotechnics... After each show this stuff gets rapidly torn down, shipped ahead overnight to the next venue, and set up by local technicians who are not familiar with it before the band and their own roadies get there.
Not only do the locals have to avoid damaging the equipment doing this, but if they don't set it up _exactly_right_ it won't sound right, may fail halfway through the show, or even kill someone. Pyrotechnics are dangerous,stages are dangerous, just the lights can start fires or explode sending glass shards flying, or simply fall on someone from 40 feet up, or give you heatstroke bad enough to triggerheart attacks. Evena miswired microphone can kill you.
This stuff is so complicated it's been compared to flying a jumbo jet that gets dismantled and shipped ahead at each stop, and then you have to go up in it and fly in circles for a couple hours. If it was put together by people who didn't follow the instructions, or did a few steps how they think it should go instead of how you said it should go, bad things happen in front of (and sometimes to) very large crowds.
So experienced touring musicians provide the locals with detailed instructions to be followed _exactly_ about how to set up their show in each new venue. And the really experienced ones bury a canary item a couple dozen pages into the checklist, so that when they walk into their dressing room and see the canary they know the instructions were followed exactly and that it's safe to perform. If they DON'T see the canary item, or the canary item is prepared wrong, the rest of the instructions weren't followed correctly either and their equipment isn't going to work.
Of course people who don't understand what's going on attribute it to the musician being crazy. Refusing to perform over a missing bowl of green M&M's? What a prima donna... And there you see theDunning-Kruger effect in action. One's own lack of knowledge making the experts seem stupid.
~ Rob Landley (Original Post Here)