Menotti’s Amahl and the Night Visitors belongs to that curious class of works that are widely supposed to be ubiquitous but are actually quite rare. If you were born later than the 1970s you might never have encountered it in the wild. I can’t recall a production by a major UK company this century, and even recordings are relatively scarce, with the 1955-vintage original NBC TV production, conducted by Thomas Schippers, still commanding a fairly small field. So this new film of Stefan Herheim’s recent German-language staging for the MusikTheater an der Wien is welcome, whatever one’s reservations about the production.

We’d better deal with those reservations right away. Critics shouldn’t really deliver spoilers, so consider this a Parental (or Grandparental) Advisory, particularly if – as is wholly understandable – you’re thinking of sharing this warm-hearted Christmas opera with young children. In Herheim’s concept, little Amahl is a terminally ill cancer patient, watched over by his anguished mother in a realistically presented hospital ward. He imagines the hospital staff to be the Three Kings, and at the end … well, let’s just say that he doesn’t exactly go to Bethlehem.

As usual with Herheim, it’s handsomely staged; in fact it’s playful and often very beautiful, with Sebastian Ellrich’s sets opening out, magically, to reveal a starlit sky. Your reaction will depend upon whether you’re ready to respond to the opera as tear-jerking tragedy rather than feel-good family treat. On its own – or rather, on Herheim’s – terms, it’s quietly devastating, and many will feel that Herheim’s dramaturgy is an effective foil to the sweetness of Menotti’s score. I was more troubled by the ballet sequence: this is one opera in which I genuinely can’t see any musical or dramatic justification for a simulated sex act. It’s as if Herheim can’t help himself: he’s an important modern opera director and inserting gratuitous sex scenes is just what important modern opera directors do. Happy Christmas, children!

Regardless, it’s all done with the highest possible production values and the commitment and artistry of company and cast are beyond question, with Tempu Ishijima quite wonderful as Amahl. He’s a member of the Vienna Boys’ Choir, apparently, and not only does he land right on the note throughout the opera, but his voice has a plangent, penetrating sweetness that perfectly complements his understated, naturalistic acting. Dshamilja Kaiser is powerfully affecting as his Mother; there’s a darkness as well as an immediacy to her mezzo that gives a passionate edge to her sorrow. The Visitors sing warmly and play their parts with a drollness that falls just the right side of parody. Magnus Loddgard, conducting, gives everyone space to breath, finding a deep, luminous lyricism and bringing out Menotti’s zingier colours (the Visitors’ deliciously Prokofiev-ish entrance march gets reprised over the curtain call). As far as I can tell, the English subtitles faithfully reproduce the original libretto.

To summarise, then: if you’re a German speaker, a Herheim fan or you’re simply intrigued by the idea of an unsentimental adult reimagining of Amahl, this has the field to itself and it’s unlikely to be bettered. For everyone else: well, Schippers and co retain their crown, which is saying something for a film and recording that’s nearly 70 years old. Personally, I’d watch both; just not, perhaps, in front of the children.