Back in 1927, Ernst Krenek hit the mood of the times for imaginative yet up-to-date opera with Jonny spielt auf (Op 45). Forty-three years later, in 1970, Sardakai (Op 206) had a rougher ride. A modern version of Così fan tutte might be enjoyable. Even quotations from that work, as well as Gluck’s Orfeo and Beethoven’s Fidelio, within an otherwise contemporary idiom, could suggest a degree of postmodern chic. But combining distinctly old-fashioned Schoenbergian music with a production style that involved depicting the leader of a rebellion against Queen Sardakai as Fidel Castro didn’t go down well with Hamburg’s solemnly radical students. The opera was roundly booed at its first performance, and even Krenek’s sympathetic and perceptive biographer, John L Stewart, has concluded that a work intended to be lightweight “worked too hard for its laughs”, not least because the composer’s own libretto – whose complexities and confusions resist summary here – amounts to little more than “larkish nonsense”.

So why record it in concert performance in 2000 (Krenek’s centenary year) and issue that recording six years later? As Stewart conceded, “despite its flaws the opera is funny”, and the music, at times echoing the poised satirical world of Schoenberg’s improbable 12-tone comedy Von heute auf morgen, is rarely dull. Though never blossoming into the full-blown lyricism of those number operas to which Krenek alludes from time to time, it has a decent degree of melodic eloquence and the generally excellent cast manage to avoid ponderously over-pointed delivery.

It’s not always easy to distinguish the three sopranos, but that simply confirms how good they all are, and although tenor Jürg Dürmüller has beefy moments he avoids the kind of persistent vocal ham-acting that would probably happen in a stage performance. Conductor Reinhard Schmiedel keeps the whole thing bubbling along, and the recording is as well suited to the refinements of Krenek’s witty orchestration as to the vocal balances. Sadly, Capriccio has chosen such a tiny font for the three-language libretto that even those with 20-20 vision are likely to risk eye strain in trying to follow it.