Although all of these composers were active in Terezín (Theresienstadt), only the works by Klein and Ullmann were written there, though Krása reworked his children’s opera Brundibár (‘Bumblebee’) in the ghetto with new lyrics and a reduced scoring. David Matthews’s new rescoring for a nonet of winds, piano and strings uses Petr Pokorný’s suite, which pulled the main tunes together into a pleasant heptalogy. The scoring sits somewhere between 1920s Parisian neo-classicism (Krása studied with Roussel) and Hindemith, and feels a touch like a superior silent film score.

Brundibár’s historical place far outweighs the simple charms and merits of the score. Of more (musical) moment are Ullmann’s Third Quartet (1943) and Klein’s final work, the masterly String Trio (1944). Ullmann’s concentrated, sole surviving quartet (its four-in-one design lasts under 14 minutes here) breathes a rarefied air, every bar testifying to his complete mastery of quartet-writing. The intensity the Nash Ensemble bring to it matches that of their Czech rivals in Klein’s three-movement Trio, the heart of which is the variations on a Moravian folksong. This is not cellist Paul Watkins’s first recording of the Klein, having accompanied Daniel Hope and Philip Dukes in a magnificent account for Nimbus. The Czech String Trio are strong rivals, but Hyperion’s sound is superior.

This is the third recording I know of Haas’s superb Second Quartet (1925), and the competition is fierce. Hyperion provides perhaps the coolest sound of the three, slightly clinical though crystal clear. This shows the Nash Ensemble’s subtly nuanced performance in the best light, though is not enough to displace the more idiomatic Pavel Haas Quartet on Supraphon (with Colin Currie a touch more vivid than Chris Brannick in the finale’s optional percussion part); theirs is also part of a complete Haas-Janáček cycle.