Parties in opera often end very badly. Don Giovanni is dragged down to Hell after setting the table for supper. Verdi’s Un ballo in maschera ends with an assassination, while Herod’s guests in Strauss’ Salome probably didn’t realise their invitations were for a beheading. The party has provided a key framing device over the last few years for new opera at Covent Garden. In 2017 Thomas Adès’ The Exterminating Angel saw a group of sophisticated guests tear each other apart, mysteriously trapped at a post-opera soirée. Kaija Saariaho’s Innocence (staged in 2023) took place at a wedding reception, with the ghosts of a murderous atrocity as uninvited guests.

Mark-Anthony Turnage’s Festen completes an unholy trinity of bad vibes. The text, after Thomas Vinterberg’s 1998 shibboleth of Danish Dogme cinema – later a West End play – is by Lee Hall, best known for the musical Billy Elliot. Any new opera is a cause for celebration, though in this instance most of the cheer is to be found offstage rather than on it. Festen sees the family of a well-heeled hotelier (Helge Klingenfeldt) gather for his 60th birthday party, drawing back together his two sons – estranged recovering alcoholic Christian and brutish philanderer Michael – and daughter Helena. Their sister Linda had killed herself at the hotel some years prior, and, as the evening unfolds in the gaudy dining room, with sets by Miriam Buether and costumes by Nicky Gillibrand, a history of sexual abuse in the family comes to light. Between the scenes, a green sofa – the site of the abuse – looms larger with every intermezzo.

Turnage’s stage works have been preoccupied with families in different states of unhappiness: his first opera, Greek (1995), is a sinewy adaptation of Stephen Berkoff’s geezerish retelling of Oedipus Rex. The Silver Tassie (2000) is a similarly unsparing portrait of domestic cruelties. A version of The Railway Children for Glyndebourne in autumn 2025 lies ahead.

Parties, with their heightened atmosphere, suit the elevated, dreamlike mood of opera well; they provide a cross-section of generations and classes (patriarchs, youngsters, staff, servants) reflected in voice types, as well as aria-like opportunities for speeches and outpourings of glee for a massed chorus. The pared-back principles of the Dogme 95 manifesto might seem in some respects at odds with Turnage’s extravagant and extroverted musical language, but he and Hall have forged something that is compellingly crafted and wholly their own. They are aided greatly by director Richard Jones, who directed the composer’s Anna Nicole back in 2011. His cartoonish style often wrongfoots audiences with sudden eruptions of absurd or surreal humour at moments of high seriousness; he has a perverse feeling for the kind of unexpected or unbidden laughter you might encounter at a funeral.

It chimes well with the wicked, garish humour found in both text and music, giving rise to alarmingly carnivalesque tableaux. In Act one, a chilly exchange between Christian and his former lover Pia in their room is offset, stage right, by Michael and Mette – the latter a stupendous house debut from Philippa Boyle – who go from marital spat to rough, enthusiastic screwing, accompanied by silly circus music from the pit. An echt-operatic chorus in the same act is built from an argument about whether the soup is salmon or lobster, the kind of utterly banal but somehow loaded discussion essential to any family gathering, with its significance magnified by Turnage’s ingenious ensemble writing. It often feels like you are caught in a grim, obscene vortex. In Act Two a big-band conga bursts through a skin-crawling, racist invocation of Baa Baa Black Sheep, turning on Helena’s boyfriend Gbatokai (Peter Brathwaite). It’s a virtuosic sequence, in terms of both musical dramaturgy and production.

The score has plenty of variety, alongside the jazzy sonorities (lots of hi-hat and soprano saxophone) there are suggestions of Tippett and Britten. The orchestral interlude that joins acts two and three begins with a brash, sweltering blues whose musical self-confidence is stretched to breaking point, eventually exploding with anguish.

There are powerful and haunting laments, too. It is a mood that Turnage has often captured previously, such as in Blood on the Floor, an orchestral elegy for his brother Andrew, or indeed Song for Big Owl, a heartbreaking tribute for solo cello to Turnage’s composition mentor Oliver Knussen. Two scenes in particular stand out. Helena, a crystalline Natalya Romaniw, is given an aria of searing beauty in which she reads out her late sister’s suicide note, built around a simple and affecting melody. It is followed by one of two great silences in the piece, heavy with grief. Earlier in Act Two, Michael and the other guests savagely beat Christian after he screams at his parents; in the middle of this, the Grandmother sings a nursery rhyme-like melody over the top, whose simplicity is lacerating in its sadness. It’s an unimpeachable example of operatic craft.

Hall’s frank libretto gives the piece a real confrontational heft. Christian’s toast to his father accuses him directly. ‘He fucked his little children!’, he screams, traversing his entire range. A silence of extraordinary intensity follows, broken bathetically by the Grandfather launching into a rambling story. This upfront handling of abuse makes the opera the inverse of Britten’s The Turn of the Screw, where the shadowy horrors and transgressions of the past are glimpsed obliquely and suggested. Likewise in Saariaho’s Innocence, which turns on the same dramaturgical conceit of the family gathering, past violence is only revealed elliptically.

In Festen the truth is stated without euphemism or compromise, though the assembled guests pretend not to hear it. ‘I’m sorry you’re both such c***s’, Christian says to his mother and father, ‘I hope you die.’ The audience’s own reaction is under the microscope, too, drawn into this family’s conspiracy of silence: little invitation cards were folded on the backs of the seats.

The cast is precision-tooled for the execution of a premiere such as this, packed with seasoned new music advocates. They are led by tenor Allan Clayton, who previously created the title role in Brett Dean’s celebrated Hamlet for Glyndebourne, and is just as intense and riveting here. The unique delicacy and colour of his voice enables the best musical moment of the whole opera: a floated, feathery hiss of ‘leave me alone’, above an unearthly rumble from double basses. Stéphane Degout, a baritone celebrated for his performances in George Benjamin and Martin Crimp’s Lessons in Love and Violence on the Covent Garden stage, is a tough, wiry presence. He is also given a devastating climax after he administers a thrashing to Helge in the kitchen: ‘You will never see your children again!’; wife Else (Rose Aldridge) watches aghast, screaming her lungs out. Gerald Finley, who starred in The Silver Tassie , is eerily smooth-voiced as the charismatic Helge. Bass John Tomlinson, who starred in Harrison Birtwistle’s Gawain and The Minotaur, is a model of vocal clarity even into his eighth decade. He gives a scene-stealing turn as Grandpa, oblivious, anarchic and obscene. With 25 principal roles, the cast are too many to praise, but the performances are faultless, not least the Chorus. It is all driven by Edward Gardner in the pit, with the orchestra in swaggering, sweltering form.

For all this, there are a couple of question marks. Turnage’s musical language itself sits in an approachable tonal idiom. Nothing wrong with that. But the relatively straightforward harmonic palette in the background of the work doesn’t feel quite severe enough for its tough subject matter, or the wiry focus of Lee’s text. The bacchanalian elements of the score sweep one up totally, with their obscene excess, but I was left wanting more of a feeling of dread and claustrophobia, and more intimations of the incipient violence from which this whole family story is woven. A superfluous scene bridging acts two and three, in which Christian hallucinates his dead sister Linda, who appears from the sofa, the site of their abuse, to sing words by Julian of Norwich, was musically underwhelming. It felt more like an intermezzo than a confrontation, with the very chilliest parts of Christian’s psyche awkwardly appended to the end of the thrilling second act.

That the brief Coda is billed as ‘Act Three’, suggesting something more substantive and layered than one scene and scant minutes of music, disturbs the overall narrative shape, too, and leaves the ending wanting. The next morning, bloodied and shattered, Christian is back in the hotel lobby; Turnage reprises the ‘Hello’ chorus of the opening – strongly redolent of Britten’s Peter Grimes in this respect – with guests blithely coming and going. A new day dawns and nothing has changed. Helge, bandaged up, even enters holding hands with one of his grandchildren. In the film everyone sits down to a stilted breakfast, followed by an attempt at contrition, and a new start for Christian. It’s fine to dispense with these narrative elements in a reimagining, but what was missed from the conclusion for me was something frozen and piercing, capturing the mist of shame and denial that hangs over this implicated family. Perhaps the bathos was the point, but it felt somehow too easy. All this notwithstanding, composer, cast, and creative team have earned themselves quite the party.