Post War Years, Hoxton Bar & Kitchen, London

It is a brave group that opens with a number called "False Starts", but then this fresh-faced four-piece have proved their mettle by turning out on one of the quietest weeks of the gigging year – in a cold snap that has paralysed much of the nation.

While Post War Years appear to be sprinting from the blocks with some dash, this studious bunch are slowly and steadily building up a following for their synth-inflected math-pop. Last May, they sneaked out their debut album, The Great and the Happenings. Lacking the intensity on record of their closest antecedents Foals and the US outfit Battles, Post War Years have yet to make a similar impact.

From the start of tonight's set, though, they are able to grab our attention with charm and invention. Three of the band line themselves stage front: gangly Simon Critten, impish Henry Riggs and the awkward Tom O'Hare. Multi-instrumentalists all, the latter pair start with bass guitars – Riggs playing intricate top lines, while his bandmate anchors their elastic funk. Critten conjures up brass samples in some sly homage to soul power. For the set highlight, "Whole World on Its Head", his fingers tap out an abstract, beguiling, sci-fi motif.

Elsewhere, PWY seek to make more emotive impact. A paranoid undertow runs through much of their work, emerging on occasional full-blooded refrains. As in "White Lies": "It's not what you do that makes you tired, it's how you sleep at night," they accuse in unison. The group do moody, too, as they prove on the vaguely sinister "Soul Owl" that Riggs croons over a dubstep shuffle.

Palpably glowing with enthusiasm, the band clearly have a high old time, though not always to great effect. Even the memorable numbers can be best framed like Friends episodes – the one with the brass samples, the one with the birdsong, without making much more impact. Often, they concentrate too much on their own virtuosity to the detriment of the whole, most apparently when their vocals fail to gel.

Critten jokes that they are only playing tonight because they wanted to nail "Tubular", an album track they have only attempted once before live, unsuccessfully, but instead they close with "Black Morning", led by its pleasing piano house riff, another clever idea they need to flesh out. Post War Years could be on the cusp of turning into something quite special, but for now remain engaging company along the way.