There’s no denying British Sea Power’s bull-headed singularity. They followed their nomination for the Mercury, for 2008’s Do You Like Rock Music?, with an obscurant soundtrack to a 1934 film about Irish fishermen; three months ago, they pre-empted Valhalla Dancehall’s arrival with Zeus, a seven-track EP of wilful experimentation. Yet what’s surprising about their fourth album proper is its apparent lack of surprises. All the usual BSP tropes – the liberal politics, the military references, the gossamer instrumentation – are here, just with more polish. But Valhalla Dancehall is more subtle than that suggests, its careening songs coalescing to an understated concept. In the raucous agit-prop of Who’s in Control, the velvet-gloved satire of Living Is So Easy and the fearful explosion of Stunde Null, the band present British society crumpled in the gutter. They, meanwhile, are gazing at the stars, glimpsing “interstellar clouds on the Sussex downs”, creating music of exquisite, luminous beauty.