If you had never seen The Joy Formidable before, you would be forgiven for thinking they have always been doing what they do tonight. Little more than a year ago they were comfortably blowing the minds of a couple of hundred people at a time in the Barfly just up the road. But it was tough to say whether or not they would ever see anything outside those dark, grotty walls.

Fortunately for them, fortunately for us, they have never looked back. Tours with Manic Street Preachers, the patronage of Mansun’s Paul Draper and – make no bones about it – the release of a fucking huge album in The Big Roar, have helped springboard the band onto a greater treadmill heading towards inevitable ubiquity.

Tonight, the band betray nothing of their recent toilet venue history. Guest harp player Joy Smith plucks a wistful refrain to begin the evening, paving the way for the band to take to the stage and divebomb into ‘Whirring’, fizzing with energy. Admirably choosing to stretch the song out into its logical ten-minute wig-out conclusion, it’s as if they have landed slap bang in the middle of an encore, and that level of energy never lets up for the next 90 minutes. They whip up a resplendent racket, a wall of gorgeous noise, and the crowd – once made up exclusively of young hipsters, now a rainbow of music lovers – respond vivaciously.

This, the last night of their first major headline tour, can only be described as a lap of honour for the perfect grassroots-success-story band. Koko is not universally loved as a venue, but there is a grandiosity about the building that serves a purpose should you seek it. And the sense of occasion manifest in everything else about this show is only too suited to the flamboyant surroundings.

Towards the end of the show, beneath frenzied strobes, with green-eyed demons flanking the stage, a “feline choir” – complete with cat masks and red robes – creep up behind the trio, clanging bells and chanting stoically. Before the band return for their encore, the PA spouts a recording of what sounds like someone literally spanking a monkey. It’s these odd touches, these glimpses of the absurd, that make The Joy Formidable more than your average rock band. Their music may have stadium ambitions, but what makes it interesting is this taste for the freakish, an attraction to the bizarre.

Capping off the night with an immense version of ‘The Everchanging Spectrum of a Lie’, the band are in full-on party mood, inviting the entire audience for drinks afterwards, and suddenly their name seems wholly apt. The joy they manifest in their craft, as well as that which they bring about in their audience, can only be described as formidable. There’s just no going back from here for this lot.