English National Opera has arrived at the Dead City, and who, before Christmas, would have given odds that this new production of Korngold’s Die tote Stadt would ever make it this far? This is late-Romantic music-drama on an exuberant scale; it simply doesn’t lend itself to pubs and car parks (even the reduced version staged – superbly – at Longborough last summer used an orchestra of some 60 players). Korngold deals with strong emotions (grief, delusion and obsessive love) with a melodic generosity that has historically provoked the prissiest instincts of the British operatic establishment. The Royal Opera held its nose and staged a brief run in 2009, before sweeping it hastily under the carpet.

But not ENO. ‘The opera is a masterpiece,’ says ENO’s artistic director Annilese Miskimmon and for that alone I’d gladly double its subsidy. Of all the idiotic things that have been said about English National Opera since the Arts Council’s botched attempt to garrot the company last November, the most self-evidently ignorant was that it lacks a distinctive artistic profile. Rot: I’ve written before about ENO’s role in preserving and refreshing the indigenous operatic tradition, from G&S to Birtwistle.

But it’s also the best place in the capital to take the pulse of the messier European directors (Bieito’s Carmen, Horakova’s Luisa Miller), to see new-ish work that actually stands a chance of attracting a mass audience (Akhnaten, The Handmaid’s Tale) and for directors from the wider theatrical ecology to try their hand at opera and either triumph (Cal McCrystal, Simon McBurney) or implode (Emma Rice). The possibility of failure is part of what makes ENO so vital. It feels healthier – more truly theatrical – to witness ENO aim high and crash in flames than to sit through any number of slick Stefan Herheim imports or succès d’estime premières at the other place.

Which is a sort-of preliminary to saying that despite some formidable musical and dramatic strengths, this rare staging of an opera I adore, by a company I badly want to succeed, doesn’t quite come off. The strengths first: Kirill Karabits conducts, and he lets air into Korngold’s super-saturated score, freeing melodies to soar, and charging silences with the same pregnant, potent atmosphere. The composer sanctioned an elision between Acts One and Two: Karabits and Miskimmon open it out, making this the most complete version of Die tote Stadt ever to have been staged in the UK. Or rather, The Dead City: Kelley Rourke’s English translation is a masterclass in clarity and fidelity. Over and again, I found her choice of words mapping directly on to the long-familiar German originals in my head.

Miskimmon’s production, too, remains largely faithful to the composer-librettist’s conception, once you allow for the now-statutory updating to the 1950s. The ‘Dead City’ is 19th-century Bruges, and Miskimmon and her set designer Miriam Buether use mist and light to conjure some eerie, painterly stage pictures: funeral processions moving darkly through fog and twilight as, trapped in his memories and his luxe-moderne apartment, the hero Paul starts to hallucinate. Paul was played by Rolf Romei, and we were warned in advance that he had been unwell, disarming serious criticism of his singing (which sounded, in its less strained moments, like it might have a real potential to thrill).

As Marietta, the object of his fantasy, Allison Oakes dispensed glowing flurries of tone; but the two never came close to establishing the volatile chemistry that these roles require. Possibly that’s down to Miskimmon. Romei’s shuffling, cringing Paul seemed not so much scarred by grief as wholly paralysed by it – a serious problem when the entire plot is driven by his emotional transformation. Marietta, in this context, came across as overbearing and unengaged. Korngold casts the same singer as an apparition of Paul’s dead wife Marie but Miskimmon had that part mimed by a spectral, waif-like figure, completely unlike Oakes, who kept wafting on at awkward moments, as well as gesticulating from a floating coffin. Grand Guignol is certainly one way to approach this death-haunted opera, but on the first night it felt more like The Addams Family.

Perhaps it’ll bed in and gain subtlety as the run continues. Let’s hope so, because Miskimmon’s heart is evidently in the right place and ENO deserves to succeed with Korngold. And again, so much about this production is excellent. There’s great pleasure to be had from the supporting roles alone: the noble light and shade of Sarah Connolly’s singing as the housekeeper Brigitta and the lyrical ardour of Audun Iversen in the dual role of Frank and the strolling player Fritz. If the central pair ever click, the whole show will light up. In the meantime, it’s an intermittently brilliant illustration of just how important it is that ENO retains its artistic right to fail.