Kitty Muggeridge's famous line about how David Frost rose without trace could just as easily be applied to Bombay Bicycle Club. Not in the bitchy way that Muggeridge intended, but more as a statement of fact. Here we are, four years, three albums and 10 singles into their career, sales respectable rather than earth-shattering, venue nevertheless packed, but could you close your eyes and picture what the north London quartet look like? Perhaps tonight's crowd could – they are so eager to demonstrate their enthusiasm for the band's oeuvre that a mosh pit intermittently erupts, often to some profoundly unmoshable music – but you do look at the anonymous figures on stage and wonder.
On tonight's evidence, part of the issue might be that Bombay Bicycle Club can still sound like a band casting around amid the currents of alt-rock in search of a style: a bit of post Vampire Weekend African-inspired guitar here, a hint of the Killers in a keyboard line there, a sprinkling of shoegazing revival effects-pedal overload. Open Door is post-Libertines indie rock ordinaire, while Ivy and Gold, a track from their acoustic album Flaws, sounds like post-Mumfords folksiness. Still, if anyone in the indie firmament has a calling to dabble with banjos and vaguely trad arr melodies, it's guitarist Jamie MacColl, grandson of the British folk revival's original power couple Ewan MacColl and Peggy Seeger.
Whether this is evidence of musical restlessness and admirable diversity or the sound of a band for whom success came before they developed an identity of their own is an arguable point, although you can see why people like them. Whatever, or rather whoever, they sound like, it is all decorated with decent tunes – and intermittently, signs of something unique flash out. Cheeringly, those signs are mostly from recent album A Different Kind of Fix. Single Shuffle is based around a weird piano sample, equal parts Italian house screamer and pub sing-along. How Can You Swallow So Much Sleep demonstrates an intriguingly off-kilter approach to pop songwriting: the tune sort of sidles up to you and then insinuates its way under your skin. More of that and their rise could continue, and in a more distinct manner than it has thus far.