The Brothers Karamazov, Barbican, London

It's a brave (or foolhardy) man who dares to make an opera of Dostoyevsky's The Brothers Karamazov. Throughout the long first act of Alexander Smelkov and Yury Dimitrin's adaptation for the Mariinsky Theatre, the effect was a little like speed-reading it while under the influence. If you didn't know the novel at all, the seemingly reckless dash of the narrative, the dislocation of characters and ideas, will have left you feeling marooned in some grand farce. To some extent, Dostoyevsky's last novel is just that – the anatomy of a chaotic society and the human conditions driving it. But still I wonder if the composer and his librettist have got the balance right between the grimly ironic and the tragic?

Another problem with this opera is that it takes a novel of startling originality and reimagines it through music of startling unoriginality. Smelkov's score is so full of allusions and borrowings that you wonder where he comes into the picture. In the opening bars, the weight of impending tragedy is conveyed in a leitmotif so redolent of Brahms' First Symphony – in shape, scoring, and attitude – that the audience is not so much gripped by its power as bemused by its similarity. After a minute or so it's morphing into something a lot like the start of the great passacaglia from Shostakovich's Lady Macbeth of the Mtsensk District. Beethoven's Ninth is in there, too (repeatedly), while Grushenka (the glamorous Kristina Kapustinskaya) voices her romantic confusions by way of a soaring motif plundered from Tchaikovsky's Eugene Onegin. And so it goes on.

No one would dispute Smelkov's compositional virtuosity, his skill and ingenuity with orchestral sonority, but because so much of this score sounds like second-hand Shostakovich and Tchaikovsky, the immense passions embraced by the novel come across as oddly counterfeit in the opera. And when we do arrive at its emotional climax – a haunting nonet expressing the collective guilt of all its principal characters – there is suspicion that this too is somehow a parody of catharsis.

Needless to say, Dostoyevsky's colourful gallery of characters – all Russian society is here – brings out the best in the Mariinsky ensemble, with its seemingly inexhaustible supply of terrific and versatile voices. Valery Gergiev drives the proceedings with his customary urgency. But I've a feeling it is a local, not an international, event.