After enough line-up changes to make the Fall and Sugababes look like bastions of lifelong solidity, just how authentic is the Deep Purple experience in 2013? The band touring the first Purple album in eight years, Now What?!, features three-fifths of the "classic" team that recorded Smoke on the Water in 1971 – singer Ian Gillan, bassist Roger Glover and drummer Ian Paice – but certainly doesn't have the same strut. As the stage-front sheeting comes down on what might as well be your dad's pub band, with greater technical skills, you're reminded that teenage lust rock does not age gracefully. We're talking bandanas, sleeveless denim shirts and wobbly air-punches that suggest Gillan needs help just to reach the screeches in Hard Lovin' Man these days, let alone enact it.
What dates them most, though, is their stoic adherence to classic rock formulae. They slot new album tracks alongside pioneering early-70s warhorses from their albums Machine Head, In Rock and Fireball, and you can't see the join. When horny, they emit proto-AC/DC riff rock thick with unbecoming sleaze. When reflective, on tribute to their late organist Jon Lord Above and Beyond, they go portentous and prog. At all other times, they solo.
Goodness, do they solo; it's a miracle the monitor engineer doesn't get five minutes of their own. There's a futuristic artfulness to guitarist Steve Morse's instrumental paean to the space shuttle Columbia tragedy Contact Lost, but the solos are best played for laughs - as when Gillan strikes a gigantic crash out of the world's smallest gong, or keyboardist Don Airey performs a keyboard megamix of the Can Can and Roll Out the Barrel.
Most ageing plod-rockers disguise their stagnation with stage effects – spinning drumkits or rocket-firing guitars. The "spectacle" of Paice's light-up drumsticks and the Halloween mask Gillan dons for Vincent Price just aren't diversion enough. Despite a finale including Smoke on the Water, Hush and Black Night, you're reminded that although Deep Purple did banshee-voiced hair rock first, they weren't necessarily best.
