Adriana Lecouvreur, Royal Opera House, London<br/>Kafka Fragments, Barbican Hall, London

The loves and losses of theatre people and their circle swirl through the Puccini-lite music of a rarely seen opera in an opulent new production

How seriously should we take Adriana Lecouvreur? Celebrated for its actress heroine's limpid arias, and the improbable murder weapon of a bunch of poisoned violets, Francesco Cilea's 1902 opera totters awkwardly between piquant comedy and lurid melodrama, one moment aping Puccini, the next Massenet.

So much for verismo. Of the real Adrienne, her soldier lover Maurizio, Count of Saxony, and the 10-year affair they enjoyed between military campaigns, little survives the translation from life into opera. Of 18th-century Paris, with its stench and splendour, its veneration and condemnation of actresses, even less remains. What lingers is a misty notion of stardom and glamour, as elusive as the scent of those deadly flowers, and the poignant, invented character of Michonnet, stage manager of the Comédie-Française and the only man to love Adrienne/Adriana truly.

David McVicar's opulent production, the first at Covent Garden since 1906, does not have to try too hard to convey the notion of stardom. With Angela Gheorghiu as Adriana and Jonas Kaufmann as Maurizio, glamour is guaranteed. The frocks (by Brigitte Reiffenstuel) are gorgeous, the palette a muted cloud of dove-grey, bronze and rose-pink, save for Gheorghiu's buttercup riding-habit in Act II. Charles Edwards's meticulous reconstruction of an 18th-century theatre dominates the stage: seen first from behind dressing-rooms festooned with costumes for Racine's Bajazet (the silent backdrop to Act I), and later from the front, when its ornate proscenium is the gilded frame for Adriana's humiliation of her rival, the Princess of Bouillon.

If you travelled back in time and showed a 1970s audience McVicar's Adriana, the only aspect that might raise an eyebrow is choreographer Andrew George's Adam Ant-ish styling of the Act III ballet of The Judgement of Paris. In the pit, Mark Elder toils suavely over Cilea's cautious, fitfully orchestrated score. It's a thankless task. Each act begins with tremendous energy but little sense of purpose, period or colour. And with the toy-theatre concept and thin writing come paper characters: the saucy, sparring Mesdemoiselles Jouvenot and Dangeville (Janis Kelly and Sarah Castle), the pettish actors Poisson and Quinault (Iain Paton and David Soar), the corrupt Abbé (Bona-ventura Bottone) and the hypocritical Prince (Maurizio Muraro). As the jealous Princess, Michaela Schuster does a mean line in fan-tapping and bosom-heaving, tearing into "Acerba voluttà, dolce tortura" like a carnivore released from a vegan spa.

You can understand her lust, though Kaufmann's prime-cut Maurizio is a slippery, complex, political figure. His acting is refined, his singing idiomatically phrased if not idiomatic of tone. That Latin darkness still has a fake-tan tang, too covered, too self-conciously burnished, but when he opens his Alpine top register (in "Il russo Mencikoff") or croons into Gheorghiu's hair it is mesmerising.

Gheorghiu herself floats mistily through the opera, her voice now a gleaming, cossetted miniature of itself, receding into lovely whimsy. The power is still there, but she seems disinclined to use it much, and her acting is vague – a touch of Tosca here, a touch of Violetta there, with far too much hair-tossing and leg-swinging for a woman in her forties. As the wry, wise, loyal Michonnet, who sees every- thing and never reveals his love, Alessandro Corbelli captures the mixture of humour and pathos Cilea strove for but never quite attained in this vapid, two-hit, verismo star-vehicle.

First seen in New York in 2005, Peter Sellars's staging of Gyorgy Kurtag's Kafka Fragments had its UK premiere at the Barbican last week. The collaborative nature of this project cannot be over-emphasised. Dawn Upshaw and violinist Geoff Nutall's interpretation of these bitter, transcendent, aphoristic songs – the sparest of Kurtag's cycles – has a depth and intensity that conventional performance cannot match.

"Slept, work, slept, woke, miserable life." Quite. The first leap of imagination was Kurtag's: sheer, fractured, exquisite melodies that press, careen, growl, keen or wail over chill broken chords, trudging motifs, dry scratches, faint drones, virtuosic baroque figures or sobs of klezmer. The second was Sellars's: to make Kafka's words the thoughts of a suburban housewife, and translate the dreadful circularity of depression through the Sisyphean duties of scrubbing, ironing, folding, washing, mopping. I would not ordinarily want to watch anyone weep over laundry. I can do that myself. But Upshaw and Nuttall's ferocity, openness and musical discipline were simply astonishing.

'Adriana Lecouvreur' (020-7304 4000) to 10 Dec

Next Week:

Anna Picard gets her teeth into the UK premiere of Alexander Raskatov's A Dog's Heart