YOU COULD HAVE JUST PRETENDED YOU FORGOT, OZZY: Oh, that awkward problem: you're a self-respecting Prince of Darkness, and yet you've managed to agree to play a gig at the Royal Variety Performance. What do you do? You could, of course, play the gig but yell "Death to the monarchy" and splatter the audience with paint. Or take to the stage and keep quiet for a whole ten minutes. Or, you could be like Ozzy Osbourne and say sorry, Prince Charles, got a doctor's appointment I've forgotten. No way that would look like an awkward climbdown, then.