The War on Drugs @ Corsica Studios, London

The War On Drugs are about halfway through their set, the last of their current European tour, when leader Adam Granduciel announces that they’re going to play ‘Brothers’, perhaps the standout track from their critically adored new album Slave Ambient. There’s a loud cheer from the capacity crowd packed like sardines into the furnace of Corsica Studios.

“Yeah, is that your favourite?” he smiles, “It’s my favourite too.”

He glances around the tiny stage. "We usually invite someone from the audience up to play guitar on this one, but I don’t think there’s room.” A pause. “Ah, fuck it! Who wants to play guitar?” A few people glance at each other, there’s a smattering of cheers, one man shouts loudest. “Come on up!”

The new man scrambles onstage. A guitar is hastily tuned and handed to him. A moment of confusion as it transpires he’s left-handed. Granduciel asks him to play a few chords, looking momentarily unsure. (“Erm… this is a big show for us, dude.”)

But then he nods to the drummer and they launch into ‘Brothers’, and the tentative strumming becomes just a drop in a squalling ocean of sound. Fortunately, The War On Drugs can play.

Their albums are characterised by densely-layered music which Granduciel spends weeks or months fine-tuning, but live we get to see another side of them: one that’s even more raw and instinctive and happy to embrace the chaos of inviting a stranger onstage with them. What’s particularly impressive about this set is the range they muster, from the early tracks where Granduciel plays harmonica and intones his words like Dylan to the feedback-laden finale, all while retaining the clarity and cohesiveness of their musical vision.

When they first toured the UK, Granduciel tells us, they played “Yeovil, Coventry… all the big market towns.” Next time they return to these shores they’ll play bigger venues than this, but I bet they’ll still embrace each show with the same spirit of adventure and chaos.

With a bit of luck Granduciel will be on the form he’s on tonight: eyes tight shut, sweat dripping from his hair, mouth against the mic, feeling every word.