When does an operetta become a musical? Paul Abrahám’s 1932 jazz operetta Ball at the Savoy – which opened in Berlin before transferring to the West End with lyrics by Oscar Hammerstein – could go either way. Abrahám trained in Budapest and hits such as Viktoria und ihr Husar (1930) and Die Blume von Hawaii (1931) established him as the hottest young challenger to the ageing emperors of Central European operetta, Lehár and Kálmán. Fizzy, sexually liberal (divorce is a running joke) and set in a world of radio announcers and foxtrots, Ball at the Savoy is the Weimar Berlin revue-operetta par excellence (Hitler forced it offstage in April 1933).

Still, set against that a libretto by the dream-team of Fritz Löhner-Beda (The Land of Smiles) and Alfred Grünwald (Countess Maritza), and a basic plot (husband attends party with a view to dalliance; wife goes incognito to catch him in the act) whose pedigree extends through Der Opernball and Die Fledermaus right back to La vie parisienne, and Ball at the Savoy stands firmly in the great European tradition. True, it’s an infectiously jazzy score, closer to Cole Porter than to Johann Strauss. But it’s not the tangos or the comic songs that really linger in the memory: rather, the moments when genuine emotion rises, however briefly, to the surface, and Abrahám eases into another yearning, bittersweet waltz.

This complete English-language recording comes from a 2014 production by the resourceful Illinois-based Folks Operetta, and as far as I can tell it’s the only existing recording of most of the score (the original Berlin cast recorded a selection of highlights). Its strengths are comparable to those of Folks Operetta’s previous release on Naxos, Leo Fall’s Rose of Stambul – in other words an enthusiastic energy that suggests a live performance, and the inclusion of the spoken dialogue in an effective and often witty modern translation.

The full libretto is available for download but it’s entirely possible to follow the plot as you listen, and Ryan Trent Oldham (as the polygamous and distinctly un PC Turkish playboy Mustafa Bey) and Cynthia Fortune Gruel (as aspiring songwriter Daisy) have a lot of fun with the more tongue-twisting lyrics, while Bridget Skaggs is entertainingly sultry as the bombshell Tangolita. As the aristocratic newly-weds Madeleine and Aristide, Alison Kelly and Gerald Frantzen make an attractive-sounding leading couple, though it’s the stylish Kelly (along with Gruel) who really carries the show when Abrahám opens out the emotion and a soprano line needs to soar. Frantzen’s pleasant tenor is warm but underpowered, and Oldham’s tuning is sometimes very approximate indeed.

There’s also no getting around the fact that the reduced orchestration sounds raw: there’s plenty of vigour and zip but conductor Anthony Barrese doesn’t have a lot of string tone to call upon at those telling, expansive moments that make Ball at the Savoy more than just a jazz-age soufflé. It’s probably too much to hope that a recording of Barrie Kosky’s dazzling 2013 Berlin production awaits release somewhere; Kosky understands that these inter-war operettas need indulgence as well as irreverence and he has the resources to supply both. But with their limited forces and clearly limitless enthusiasm, Folks Operetta and Naxos have plugged another important gap in the operetta discography, and that’s never a bad thing.