Have you ever seen Karen O’s eyebrows? They’re normally guarded by an impenetrable ebony fringe, but I saw them the other day, indecently exposed on the cover of a magazine (along with the rest of her face), and I was shocked. A woman once so familiar had morphed into something quite foreign. It was unnerving, but also exciting, not unlike the experience of hearing the opening bars of ‘Gold Lion’ for the first time. Yeah Yeah Yeahs and an acoustic guitar? Where was Nick Zinner’s distorted buzzsaw chug?

Show Your Bones is a phenomenal follow up to the flawless Fever To Tell; the band’s evolution, distinct. A fuzzier, poppier, West Coast warmth has imbued their tweaked-out paeans to the city streets that spawned them.

What’s incredible tonight is how tunes like single ‘Cheated Hearts’ meld seamlessly with abrasive oldies like 'Art Star’, where O returns to the beer-spewing, carousing, super-limber superhero we know so well. Instead of opening their second night at the Forum with a bang, the YYYs steal onstage and tear into the guttural, gurning ‘Fancy’. As usual, O, decked out in what looks like a gold 50s-style swimsuit, holds court – the calm, flexing centre in the midst of Zinner and Chase’s gothic maelstrom. Instead of bouncing off the walls, O is now the mistress of pace. One minute she’s bending slo-mo like Gumby in a yoga class (on the country-jangled ‘Turn Into’), the next she’s emitting a selection of tremulous psycho-sexual grunts (‘Black Tongue’).

‘Warrior’ is a startling moment’s respite. Stripped of the distortion, O’s voice cracks and creaks with that mascara-smudged vulnerability she exposed on ‘Maps’, which tonight, also receives an affecting acoustic flaying.

Zinner remains a perfect foil to O’s magnetic volatility. Looking like a character sketched by Tim Burton, it seems incredible that someone so slight can tease such terrifically robust guitar lines from his instrument. As the ringing guitars from ‘Y-Control’ loop over and over, ratcheting up the anticipation, he lurks in the shadows, before stepping out with that thrumming riff which signals a sweaty pit of colliding bodies.

For a finale, they devastate ‘Date With The Night’, which still sounds like the only song to end the world with – brutal, addictive and as lethally effervescent as Magnesium in water. Which pretty much sums up Yeah Yeah Yeahs.