At last! Anyone fascinated by fin de siècle Vienna will have heard of Richard Heuberger: friend of Brahms and outspoken champion of Schoenberg and his disciples. And anyone who loves operetta will know of Der Opernball (1898), whose dashing overture was orchestrated (if Karl Kraus is to be believed) by Zemlinsky, and whose waltz-song ‘Im Chambre séparée’ is a staple of operetta lollipop albums by everyone from Anna Netrebko to Harry Secombe. You’ve probably wondered if the rest of Der Opernball is anything like as good.

Until now, though, you’ll have had little chance of finding out, because so far as I can establish this is the first complete recording in at least 50 years. Victor Léon’s libretto is a feather-light mash-up of Die Fledermaus and Così fan tutte: two wives and their chambermaid Hortense test the fidelity of their menfolk by inviting each of them to meet a mysterious stranger at the Paris Opera Ball – she’ll be wearing a pink domino. All three women attend the ball, all in pink dominoes; and you can probably guess the rest. So far, so escapist, and operetta buffs like to debate whether Der Opernball was the last masterpiece of Strauss and Suppé’s ‘golden age’ or the prototype for the ‘silver age’ of Lehár and Kálmán. For me, Heuberger’s melodic freshness and the sparkle in his eye place Der Opernball firmly in the Strauss tradition – carefree rather than nostalgic, and all the more life-affirming for it.

Still, the days are long gone when you could expect a major operetta recording to feature singers like Nicolai Gedda or Julia Varady. CPO has recorded a production at the Graz Opera; and while the cast isn’t exactly starry (and none of them sounds entirely comfortable at the top of their register), they are at least a team: playing off each other and using their voices to create character – whether Ivan Oreščanin's enjoyably bluff Paul or Margareta Klobučar’s bright, slightly twangy soprano as Marguérite.

Alexander Kaimbacher’s lightweight tenor is pleasantly suited to the sea cadet Henri and, as his beloved Hortense, Sieglinde Feldhofer has a warm, rather plangent soprano that gives the character an appealing sweetness. Together, they lean so gracefully into ‘Im Chambre separée’ that you scarcely realise it’s coming – a tribute to the Viennese style of conductor Marius Burkert. A regular at the Bad Ischl Lehár Festival, he knows exactly how light a touch this music needs, and cast and orchestra respond with alertness and grace. In these circumstances, the lack of spoken dialogue, the short running time of each disc and CPO’s desultory presentation (they supply libretto translations for Zandonai and Goldmark: why not for Heuberger?) can just about be forgiven. Gold or silver? Either way, Der Opernball is a treasure.