But Suggs and the gang are professionals, and all that matters is that One Step Beyond does what it's supposed to. A saxophone blares, thousands of limbs lose control and a handful of roadies panic.
After three minutes, the wackiest opener in live music comes to an end. "Thank you and goodnight," announces Suggs; he and his band of seasoned nutty boys having no doubt accepted that, sometimes, these things happen. "Have we got time for one more?" he ponders. Clearly, they haven't lost their sense of humour.
Curtain problem fixed, what follows is a blistering run-through of the good, the great and the downright bizarre. Because that's how Madness roll. It isn't always easy, taking to the road with a new album, knowing that, deep down, everyone prefers the oldies. But this lot are a band reborn. And they've got a cracking new record (Oui Oui, Si Si, Ja Ja, Da Da) on their hands -- one that everyone here appears to have already familiarised themselves with.
Indeed, there is no right time to take a trip to the bar. Well, there is one moment. It involves guitarist Chris Foreman belting out an embarrassing cover of the Beastie Boys' Fight For Your Right. That little glitch aside, Madness in 2012 is a captivating live force.
A suited and booted Suggs (always an effortless vocalist) is still throwing shapes and tossing out punchlines. Chas Smash is still by his side. And the rest of the troublemakers keeping the dream alive are in terrific form throughout; Foreman and the lads' signature ska riffs and heavy brass arrangements rounding off a suitably ecstatic airing of timeless, Madness pop.
It Must Be Love will always warm hearts. My Girl 2 is just as good as its predecessor. And then there's Baggy Trousers, and the marvellous House Of Fun -- two numbers that bring out the child in every audience member. Some of them even dressed for the occasion (black ties, shades, trilby hats). Nobody went home unhappy. Wonderful stuff indeed.