Sigur Rós – Kveikur

Loose and roaring, Brennisteinn – the opening gambit of Sigur Rós' seventh studio album – is the sound of the band getting nasty. Beneath Jón Þór Birgisson's languageless vocals (by now so familiar that they seem vaguely embedded within us, elemental even), a thin, watery layer of strings tries in vain to assuage a byzantine bass line that - fed and re-fed through distortion to the point where it's begun to corrupt and pucker – hulks and strains at its shackles.

There's an abandon to the cannoning, imperfect percussion – wild and resounding, as though recorded in a cave – that might surprise those who've become accustomed to thinking of the Icelandic trio (keyboardist Kjartan Sveinsson left last year) as purely pedlars of soaring, glassy Gaian ballads. It sets a rupturing, snarling tone that continues into album highlight Hrafntinna, with its clattering metals and roving vocal; into Ísjaki's barelling drums, the flatlining morse code signals of Stormur, and the foghorn and cautionary choir of the title track.

They've not ditched the acrobatic anthemics, of course – Rafstraumur is as good as any of their back catalogue epics to stand on top of a mountain and scream to, or whatever it is you imagine yourself doing at the end of the world – and it's still, ultimately, Sigur Rós; but overall, Kveikur is their most teeth-out release for a while.