Gnarls Barkley: Hammersmith Carling Apollo, London, Friday, July 7

Sitting comfortably for Gnarls’ first ever British headline show? Then they’ll begin…

Welcome to Danger Mouse and Cee-Lo’s School Of Rock. Today’s lesson? How to prove that your history-making, nine-week reign at Number One was with the undisputed Single Of The Year. Attending today’s class will be DM’s collaborator Damon Albarn, Super Furries’ Gruff Rhys, NME and a theatre of the faithful and the curious.

It’s also GB’s first ever proper British headline show. You figure they know they have to prove that they’re here for the long haul, with tonight’s debut headline London show being moved by a band of Americans in the hope England qualify for a World Cup semi-final. Talk about people pleasing.

But anyway, yes, School Of Rock. The 14-strong band (strings, brass, backing singers, the works) lumber on to the Hammersmith stage dressed like Daz Sampson’s freakshow gone strangely right; like overgrown schoolkids in pigtails and red and black stripey stockings. They go into an impromptu rendition of Pink Floyd’s ‘Another Brick In The Wall (Part 2)’, with hands in the air and a general kookiness that makes them look a bit like Manga animations. And then their masters emerge, Danger Mouse taking up a sci-fi mixing plinth, keeping his head-down like the velvet revolutionary he is. And on the opposite end, Cee-Lo Green working it like some sort of falsetto sex monkey. It’s straight into the short sharp shock of southern fried hip-hop ‘Go Go Gadget Gospel’ followed by the futuresoul ‘Who Cares?’; two, but not all of Gnarls Barkleys’ constituent parts.

“Do you wanna hear a scaaaaaaaaary story?”, yelps Cee-Lo. “A story about a booooogie monster?”, before a clattering ‘Boogie Monster’. But it’s not until souped-up Violent Femmes cover ‘Gone Daddy Gone’ that things come spectacularly to life, letting this motley crew loose on a punk-rock tune that finally gives them some proper velocity, and the show ignites. We know that one already of course; the real surprise in GB’s relentless mission to the heart of Planet Eclectic comes with set ender and soulful run through ‘There’s An End’ by Britfolk oddball and Jack White’s mate, Holly Golightly. This is all part of a slow build, of course – sensibly, the two pop-song heavyweights are rammed together and saved ’til last, like a great big fluorescent apopalypse; and the good news is that immenent Motown-in-space single ‘Smiley Faces’, all ’60s pop, fingerclicks and wandering melodies, already feels almost as much of a modern classic as ‘Crazy’ – obviously the reason most people turned up tonight – but nowhere near an albatross yet. Compared to its sinister, airtight recorded version, this is a low-slung, funked-up version that’s a lot sexier than a man singing about a nervous breakdown really should be.

Then, you imagine just because they have time to fill, they all come back and encore with ‘Transformer’ and the swollen, ominous ‘Storm Coming’, neither of which are the strongest tunes on ‘St Elsewhere’, or even the biggest, but by this point, everyone’s locked in such a state of rapture that they neither notice or care. And, OK, this might not technically be hip-hop, but both of Gnarls Barkley originated in a genre that has consistently failed to be any good live. This, however, is fabulous; more like an old-time soul revue than a reckless PA by some chart stars – which would have been the easier option by far. But as Danger Mouse has proved over and over again, he’s not one for lazy conformity.

And it’s all over in 45 minutes. ‘St Elsewhere’ only goes on for 30 – which, if we’re honest, should be the optimum length for any rock show – and even if they had been rubbish, we wouldn’t have had time to get bored. And just like the deleting of ‘Crazy’, it’s proof that Gnarls never like to outstay their welcome. Which is a good lesson for us all. Class dismissed.

Dan Martin