But in the 1920s and the fierce dawn of modernism, Ernst Krenek was perhaps out to prove what was possible in his purposefully unlyrical Orpheus und Eurydike, the third of his 20-plus operas and rarely heard between its 1926 premiere and this 90th-birthday concert performance at the 1990 Salzburg Festival. Though the opera represents an important stage in Krenek’s evolution towards Jonny spielt auf, I don’t see it taking its place alongside Monteverdi and Gluck.

The source material is the 1921 play by Oskar Kokoschka, a rather forced marriage between Maurice Maeterlinck and Hugo von Hofmannsthal with realistic, philosophical-minded human beings in an anti-realistic setting full of minimally motivated events. When Eurydike is abducted by furies for a seven-year sentence in the Underworld, we might think of the Stalin purges except that she is paroled after five years, confesses her unfaithfulness while away but finally achieves resolution with the tortured Orpheus via a ghostly visitation.

Lacking the jazz influence that gives Jonny spielt auf gritty tension, Orpheus und Eurydike shows the composer struggling to say what he means. Tonality – and the lyricism that often goes with it – is part of the mixture in his typically wide-reaching vocabulary, but less so here than in other works. Immediately after the compact, inventively scored Prelude, what follows has vigour but murky expressive intent. The orchestra periodically explodes with similarly obscure significance. Atmosphere is minimal; this is theatre of the mind. Monologues have rhetorically brilliant moments but wind down with little sense of theatrical pacing.

Krenek’s characterisation of Eurydike has dimension, with her halting manner as she emerges from the Underworld and in her confession of unfaithfulness to Orpheus. Her guardian Psyche is effectively characterised when the Furies first abduct Eurydike. But only in the Act 3 mob-against-Orpheus scene do we hear the more expressively confident music of later Krenek.

The opera could benefit from a more comprehending performance. Is Orpheus supposed to sound as if he’s constantly under siege? So it seems with Ronald Hamilton. Dunja Vejzovic goes into the Kundry zone as Eurydike but scales back for some attractive moments. The most appealing singers are Celina Lindsley and young Bo Skovhus, whose brief portrayal of the Fool is the most cleanly articulated performance. The score’s big moments are well in hand under Pinchas Steinberg, though voices and orchestra maintain an aural distance. Add to that the German-only libretto, and this recording is a mixed blessing. But without it we might never know this opera exists.