Noah and the Whale, Koko, London

Noah and the Whale are, it seems, a band conflicted.

Shortly into the London leg of their UK tour, front man Charlie Fink announced that he'd like to dedicate the next song, "Beating", to anyone who ever saw them play The Old Blue Last, a dingy east London pub and a staple venue for any new band. Quickly realising that he had just alienated most of his new-found audience, he reconsidered: "Well, actually, it's for all of you."

Of course, the new audience is a result of their infectious pop-folk summer smash, "5 Years' Time". So ubiquitous has it become (helped along by lending it to a number of adverts and television shows) that their crossover into the mainstream consciousness threatens to alienate their original fan-base. This conflict could be seen in the crowd. Yes, the prerequisite brogue-footed, plaid-clad indie kids were accounted for, but, more surprisingly, also present were the more mature after-hours office crew, testimony to the impact of their monster hit.

The band vehemently deny accusations of being twee, brought about by their penchant for wearing blue and yellow, their use of ukulele and whistling, and their love of oddball directors. Yes, some of the tunes are upbeat, but their album, Peaceful, the World Lays Me Down, is rather incongruously filled with leitmotifs of love, decay and death. Fink may be no Nick Cave, but he can capably write about the loneliness of the heart.

Tracks including "2 Atoms in a Molecule", "Shape of my Heart" and "Give a Little Love" were stripped down and accompanied by Fink's lugubrious tones and a rousing violin. A sombre mood quickly enveloped the crowd. A melancholy new song, "Stranger", was tried out. Is this more earnest, mature sound their future?

After each song the crowd anticipated the summer hit, but Fink kept denying them. "'5 Years' Time'," shrieked a girl from the balcony eight tracks in. Eventually the band conceded and the audience got to have the dance-off they'd been waiting for.

Like their song "2 Bodies 1 Heart", perhaps the band can bring together the two camps. Their original fans will forgive the band's cashing-in. Conversely, those who bought tickets just to hear the big hit will come to appreciate the darker side of the band. Anyhow, it's a wise move to appease the two if Noah and the Whale want to be entertaining sold-out venues in five years' time.

Touring to 13 November ( www.noahandthewhale.com )