Every so often, very rarely, a band comes along with the power to hold an entire crowd in the palm of their hand. One such group are Iceland’s Of Monsters and Men.

In a gig which, at times felt more like a religious revival meeting, the capacity crowd at Oxford’s O2 Academy last Friday clapped, sang and cheered as one, while Kelflavik’s finest delivered a set of rousing folky-rock which grew more anthemic as the night progressed.

Despite the early 8.30pm start time, the atmosphere was electric. Even the irritating chatterers in the crowd were silenced as the band, playing from a stage decorated with the Icelandic cross, built to an early crescendo with the beautiful King and Lionheart – written by the band’s tongue-twistingly named frontwoman Nanna Bryndís Hilmarsdóttir about being separated from her brother. The interweaving of Nanna’s sweet, cracked voice with the smooth tones of chunky co-frontman Ragnar ‘Raggi’ Þórhallsson gives each song an intimate quality, as if we are party to their own private conversation.

They kept the pace with Lakehouse before kicking in with their best-known tune, the joyously conversational Little Talks, eliciting from the crowd a sea of arms, joyful singing and some spectacularly out-of-time handclapping.

They brought the set to a close with the drivingly rhythmic Six Weeks, starting in typical Of Monsters style, with a whisper and ending in a shout and a crash of guitars and blast of feedback.

Their rootsy sound has earned comparisons to Mumford and Sons, and while there are similarities, the Nordic six-piece go way beyond the formulaic, button-pushing sub-folk of the British banjo-botherers. A more obvious comparison would be with Montreal’s baroque-rockers Arcade Fire, with their keen sense of narrative, slow-burning towers of multi-instrumental pop and epic euphoria.

But Of Monsters do quiet and subtle just as well, as on their melancholy encore opener Sloom with its closing lines: “I met a man today and he smiled back at me... now there are thoughts like these that keep me on my feet, that keep me on my feet.”

“We want you all to join in on the singing with this one”, said Nanna as they wound up the show with the slow-building Yellow Light — a work of fragile beauty which rises into a glistening climax, made all the better by hundreds of O2 Academy punters singing gently along. And together we were beautiful.

Tim Hughes