The Echo, Los Angeles, August 1

There’s something particularly Anglophilic about Alt-J’s intelli-indie quirkiness, a starry-eyed wub-step as eccentrically English as Syd Barrett nipping down Corsica Studios for a midweek bosh-up before heading home for a ketamine-laced cheese toastie. Yet, just like Danny Boyle’s eccentric Olympics opening ceremony, this Cambridge four-piece run the risk of simply not being understood in America. This a country where acceptable oddness is turning down a free refill of Coke at brunch.

Marvellously though, tonight’s sold-out Los Angeles crowd don’t just get Alt-J and their spiralling math funk, but yank them into that special place in their hearts normally saved for In-N-Out Burger and prescription medication. Nothing has been lost in translation here at The Echo. Even the knicker-dissolving raunch of ‘Tessellate’ – the sound of an erotic boating weekend on the Norfolk Broads with Wild Beasts wearing nothing but partially unzipped cagoules – reduces the audience to a shrieking pile of pulsing hormones. If we didn’t know better, we’d be well within our rights to assume that Drake had just slunk onstage in a thong made of cupcake frosting. And hushed as it is, even the song’s sublime a cappella intro wins out over the booming beats seeping up through the floor from the dub reggae night taking place downstairs.

If the punters are enjoying themselves though, it’s nothing compared to the band. Frontman Joe Newman endears himself to the crowd even further with his perpetual Hugh Grant-ish graciousness. He thanks everyone for showing up after practically every song.

Alt-J’s Where In The Hell Did That Come From Debut of the Year™ ‘An Awesome Wave’, isn’t officially released in the US until next month. However, such a minor trifle hasn’t stopped fans from learning all of their lyrics by heart, leading into a demonstrative sing-along to the trickling future-flamenco of ‘Matilda’ which sees Joe’s grin extend to super-smug Cheshire cat widths.

Swooning and wide-ranging crotch-twitching is swapped for a small but perfectly formed, head-bopping rave down the front for ‘Estocada (Something Good)’ while the scent of California homegrown seeps through the venue.

Alt-J have already had an incredible year – their album went Top 20 in the UK. It’s too soon to say whether they can do the same in the US, but judging by tonight, there may be no coast, landmass or city safe from their wave.

Leonie Cooper