I went twice to Rusalka: Saturday morning’s general rehearsal of Dvořák’s ‘lyric fairytale in three acts’ was greeted with rapturous applause. Not a hint of a jeer, no sign of a boo. Some fabulous singing and a young conductor to die for.

There were, though, murmurings of discontent around me in the Royal Opera House amphitheatre and I wasn’t surprised: this was certainly a curious production of a flawed operatic masterpiece.

Rusalka is a water nymph who wants to experience human love and sacrifices her voice to be transformed. And all does not end happily ever after. Although the opera, loosely based on Czech fairytales and Hans Christian Andersen’s The Little Mermaid, contains some of Dvořák’s loveliest music, it’s a particularly tricky work to pull off, presenting staging and production conundrums not helped by its lead singer being mute for much of the middle act. This might help to explain why, after its premiere at the turn of the 20th century, it has had relatively few outings outside of Prague and, while I remain adamant that it is one of the pinnacles of Czech opera, it is still something of a rarity in our great opera houses.

I’m afraid I missed David Pountney’s fabled 1983 ENO production but, of the four I’ve seen, three have been house premieres (the odd one out being at Prague’s National Theatre), which points to a neglect of which Dvořák’s music is wholly unworthy .

But it’s difficult and the thought of presenting Rusalka straight doesn’t occur to many directors: they want to explore the psychological overtones, though for Glyndebourne’s premiere in 2009 Melly Still concentrated on producing one of the most visually beautiful opera stagings I’ve seen, uncomplicated by layers of psychology. Later the same year Norway’s Glaswegian opera director Paul Curran ferreted deep inside the mind of his Rusalka, a pubescent adolescent whose emerging cravings saw her entering a looking-glass world, with an awful lot of beds, where her youthful vision of undying love was challenged by the subtler workings of her subconscious. ‘Rusalka is about a little girl growing up, trying to become an adult, trying to become a woman and all the problems that happen there,’ he said.

So, I suppose, why not set Dvořák’s sometimes incandescently beautiful music in a ruby-red brothel, with the wood nymphs as bored whores and the witch  Jezibaba as an uncompromising madam? Why bother to have a moon for Rusalka’s lovely ‘Song to the Moon’? After all, here we weren’t by the lake: we were indoors in what was later to become the brothel, but there was a warm amber glow, so I suppose that could pass for moonlight. The deep waters remained hidden below a trapdoor at the front of the stage, though marine creatures were occasionally screened on the backdrop.

OK, it was bizarre, but let’s be fair here. I go to the opera house to be challenged, to have my preconceptions tested and sometimes disorientated. And this was by no means the strangest setting I’ve experienced:  ENO’s highly disturbing A Midsummer Night’s Dream was far more grotesque and perverted, but I will never forget it and it will colour my future perception of Britten’s opera no matter what different productions I may see.

Of course I could see why much of the rehearsal audience were perplexed. And at Monday night’s premiere that perplexity boiled over into something else. When the production team came on for their curtain call the healthy applause for the singers was replaced with a chorus of boos the like of which you just don’t hear at Covent Garden. Since directors Jossi Wieler and Sergio Morabito’s work was controversially received when first seen at the Salzburg Festival in 2008 this should not, perhaps, have come as too big a surprise. The team laughed it off.

Now, while I can’t yet find much validity for this interpretation, I’m not willing to discount it out of hand. However much psychobabble always seems to surround productions of Rusalka, it is difficult not to view it as some kind of rite of passage.

And there was much to marvel at here, provoking pleasure which was not diminished by the sometimes tawdry curiosities of the staging. Camilla Nylund is an exciting singer whose voice I missed while she was mute. And both Alan Held’s Vodnik  and Bryan Hymel’s Prince were alone worth two visits in the space of three days. But the crowning glory of Covent Garden’s first Rusalka is the fabulous playing of the house orchestra under the direction of the most enticing young conductor I’ve seen for a long time. This was the house debut not only of Rusalka but of the French-Canadian Yannick Nézet-Séguin, who galvanised the forces at his command into extraordinary feats of musicianship. I can’t wait to see more of him and if you can get a ticket it’s worth it just to see this maestro (albeit his trousers seemed to be about six sizes too big), this orchestra – and this cast. And if you are baffled by the sets, by the production, just have a think about how you’d like to present Rusalka.