From Atul Gawande's The Checklist Manifesto:
'I heard the story behind rocker David Lee Roth’s notorious insistence that Van Halen’s contracts with concert promoters contain a clause specifying that a bowl of M&M’s has to be provided backstage, but with every single brown candy removed, upon pain of forfeiture of the show, with full compensation to the band. And at least once, Van Halen followed through, peremptorily canceling a show in Colorado when Roth found some brown M&M’s in his dressing room. This turned out to be, however, not another example of the insane demands of power-mad celebrities but an ingenious ruse. As Roth explained in his memoir, Crazy from the Heat, “Van Halen was the first band to take huge productions into tertiary, third-level markets. We’d pull up with nine eighteen-wheeler trucks, full of gear, where the standard was three trucks, max. And there were many, many technical errors—whether it was the girders couldn’t support the weight, or the flooring would sink in, or the doors weren’t big enough to move the gear through. The contract rider read like a version of the Chinese Yellow Pages because there was so much equipment, and so many human beings to make it function.” So just as a little test, buried somewhere in the middle of the rider, would be article 126, the no-brown-M&M’s clause. “When I would walk backstage, if I saw a brown M&M in that bowl,” he wrote, “well, we’d line-check the entire production. Guaranteed you’re going to arrive at a technical error. . . . Guaranteed you’d run into a problem.” These weren’t trifles…The mistakes could be life-threatening. In Colorado, the band found the local promoters had failed to read the weight requirements and the staging would have fallen through the arena floor.'