"Welcome to the strange new world of Keane," says Tom Chaplin ominously. It has been six months since the east Sussex trio last played a London show - save for an invite-only preview of their new album, Under an Iron Sea, in the bowels of London Bridge station - and on first glance, it looks like business as usual. Chaplin's obligatory black shirt is tucked into his black jeans, and his cherubic curls bounce about his face as he vigorously shakes his head to Tim Rice-Oxley's soaring keyboard melodies.

But Keane aren't the breezy band whose debut album, Hopes and Fears, provoked devotion and scorn in equal measure. Burnt out by a blaze of glory that included an appearance at Live 8 and a support slot with U2, the band almost split up. Though Oxley-Smith has admitted the band wanted "to kill each other", tonight, as he and Chaplin sit at opposing keyboards for the rolling instrumental The Iron Sea, the only tension lies within the layered darkness of their new material and its uncomfortable relationship with the band's chart-friendly image.

Swathes of shivery melodies, three-part harmonies and fragile vocals mark Keane's intense mood. Shoulders hunched, head hung low, Chaplin has a pained expression on his face during Leaving So Soon? He controls his rich, note-perfect voice as skilfully as Keane manipulate the crowd's emotions: the low of The Frog Prince is followed by the cathartic highs of Bedshaped and This Is the Last Time.

Although Chaplin still hits those trademark big notes, he can't disguise the lack of tunes on Under the Iron Sea. There's nothing to match the sublime Somewhere Only We Know. You're left with the dragging feeling that Keane want to be the next Radiohead rather than the new Coldplay. Only Is It Any Wonder, with its blitz of keyboard-generated, shrieking guitar chords, matches their lofty ambition with their ability to make great pop songs.