Two difficult rarities anchor this release. Most challenging is the first recording of Peter Eötvös’s 2020 Trio, written as a memorial for viola player Christophe Desjardins. It’s a compact work with an intricate palindromic and canonic structure (unfortunately, barely alluded to in the notes). The part for each instrument is grounded in a different 10-pitch row; the rows enter in staggered fashion and move slowly through the piece, once forwards, once backwards. The pitches are not heard singly, as in a Second Viennese work; rather, each dominates a fragment, from one to 11 bars in length, where it is manipulated – always with a blinding array of colours – until the next fragment takes over.

Unfortunately, this process, not to mention the other knotty structures layered upon it, is imperceptible without access to the score. And even then, the music’s organisation is visual rather than audible. Still, if you consider the framework to be a purely compositional expedient (guard rails for the composer) rather than an expressive device, then the Trio works powerfully, for even if you don’t understand how it’s put together, the pain of loss is palpable.

Ysaÿe’s Trio, written in 1927 and not quite so rare, is complex, too, but in a less abstract way. A restless, richly contrapuntal dreamscape, it may remind you in spots of Schoenberg’s Verklärte Nacht, although its harmonies are more apt to destabilise any sense of a tonal centre. True, it’s short on melodic appeal; but if you’re responsive to post-romanticism, you’ll find that, as it swings precipitously from introverted brooding to extroverted audacity, it fully grips your attention. The other two works, less taxing and more familiar, add a welcome respite to the programme.

The disc brings together works of such varying demands that it serves as a stunning calling card by advertising the range of the group’s sympathies. From the wrenching dissonances of the Eötvös to the cheeky off-kilter rhythms of Dohnányi’s opening March, from the saturation of the Ysaÿe to the transparency and uncharacteristic geniality of Kodály, this group – with their gorgeous tone, finely judged balances and quick reaction time – capture every shift in mood and colour with confidence and commitment. Fine engineering, too. The album’s title, ‘Treasures’, is unusually apt.