Arctic Monkeys, Roundhouse, London

Arctic Monkeys' six years of success shows in their singer's posture. When "I Bet You Look Good On The Dancefloor" made them a phenomenon in the last months of 2005, Alex Turner hunched his head as if he was wading into a hurricane. That difficult musical adolescence was smoothly survived. Now, already promoting the band's fourth album, Suck It And See, he is an urbane, straight-backed young millionaire, character and creativity seemingly intact. The withering working-class reportage of debut Whatever People Say I Am, That's What I'm Not, with its Alan Sillitoe-derived title, was dumped as soon as he left that world. The band's wider cultural resonance went with it, replaced by a more hermetic curiosity in the intricacies of songcraft. Each album since has been a little bit different... and a little bit worse.

Tonight's relatively small gig as part of the Roundhouse's iTunes Festival suits them perfectly. Turner can look quizzical at festivals and stadiums, as if such giant success isn't part of his plans. Here, every move connects with the swirling, loyal moshpit. He's still a neutral presence for a frontman, only his strong Sheffield voice standing out. Though songs such as "Crying Lightning" attack fakers with lacerating observation, there's little overt emotion, any confessions secreted behind a growing tendency towards lyrical nonsense. Instead, he's subsumed into a band with more musical precision than any of their British peers. Just watch Matt Helders agilely clobbering the drums as "Pretty Visitors" slows then sprints, or listen to the new album's "All My Own Stunts" almost – but not quite – crashing in a heap as they negotiate hairpin tempo turns.

"I Bet You Look Good On The Dancefloor" seems set to be almost thrown away midway through the set, a curio from an outgrown past, until the crowd join in to shake it back to life. Jamie Cook's phased psychedelic guitar and recent single "Brick By Brick"'s experiment in intricate dumbness sum up developments on Suck It And See, played extensively and well-received here. But the emotional climax is when the crowd seize "When The Sun Goes Down" and sing it with heartfelt power, leaving the band to strum gentle accompaniment. The working-class narratives of their debut remain the lifeline between the Monkeys and the masses.