Sono Luminus’s recent reissue of Anna Thorvaldsdottir’s debut album on Innova, ‘Rhízōma‘ (2011), served as a good reminder that while the Icelandic composer has made the symphony orchestra her own, her chamber music is cut from the same cloth and somehow sounds with much the same combination of immensity and intimacy. The Spektral Quartet are rightly proud that they managed to order the Icelandic composer’s first string quartet even before the Berlin Philharmonic got on to her commission schedule.

Here, in three movements, is the result: Enigma. Doyle Armbrust’s booklet note posits a potential interpretative take-home in the idea that ‘you will ultimately be met with the emancipating and terrible truth that our lives reside somewhere in the borderlands of light and dark’. In this composer’s music, that was ever thus but the extent of her colour-derived thinking is thrust into focus by the bare bones of the string quartet. We hear the transformation of a single string note from harmonic to scratch to col legno, passing through everything in between. Fundamental sound is never not altering before our ears.

The whole piece is pulled as if magnetically by a weighty chorale, bringing to mind recent work from the Icelandic composer-conductor Daníel Bjarnason. After the first movement has splintered into a tight weave of extended techniques, the chorale returns heavier in a second movement that strips down and then rebuilds. The frantic, melismatic and momentary instrumental fidgeting that takes root at 6'05" is an evocative Thorvaldsdottir fingerprint, pitted at an oblique harmonic angle to the now glacially moving chorale. The zing of the movement’s final chord – its internal intensity subjected to sly fluctuations by the musicians – prove that even on a tonal harmony this ensemble is ‘spectral’ in more than name.

The slow-motion counterpoint of the third movement seems not so much a search for harmonic resolution – which would be perfectly viable, given what we’ve heard – as a coming to terms, a weighing up. The tonal centre is stronger than ever, if only to be tugged at or nagged before the composer reminds us that there are plenty of means, other than harmonic, with which to resolve the piece once and for all. Nobody interested in contemporary Nordic culture should be without their Dreaming or their Aeriality records, but as an appendage – and a useful X-ray of some of Thorvaldsdottir’s structural thinking – this is well worth hearing.