A very concise, two-act opera which tells a bleak wartime tale of sacrifice, rarely performed and never realised to the satisfaction of its own composer. You could be forgiven for thinking I was describing something from 20th-century Germany, perhaps an expressionist work taking after Berg’s Wozzeck or similar. You’d be wrong. It’s by Donizetti, and English Touring Opera are currently presenting this opera’s first ever professional British production, having started their tour this weekend at Hackney Empire.

The Siege of Calais, just to clarify, is not quite what you might expect from earlyish 19th-century Italian opera, especially for both its punchiness and its bleakness – two respects in which this particular version has been considerably enhanced. The original conclusion, dismissed by director James Conway as “not credible”, is done away with altogether: Act II ends with six citizens of Calais preparing for certain death, and that’s where the tale ends here. The omitted Act III would have seen the citizens suddenly redeemed in time for a surprise happy ending. Conway also reintegrates two arias from Act III into the first two acts. These significant alterations make this Siege of Calais a considerably different one from that at its 1836 première – but this has all been done with eyes firmly focused on what will make for the most convincing dramatic work today, and in this respect, the production finds a genuine kinship with the Italian dramatists of its (original) time.

The opera’s first crowds would have been transported back to 1346, when a successful English siege of the French port of Calais became a key event in the early history of the Hundred Years’ War. Conway asks a little less imagination of the audience here, updating the action to the more recent siege of Stalingrad. There is sufficiently little historical detail in either the libretto or the staging that it’s a seamless shift, and the set is excellent, a huge, sinister metal pipe dividing the city from its besiegers. The four scenes each go by in a flash, telling brief and more or less unrelated stories illustrating the noble spirit of the resisting French, and the concluding scene – in which six citizens prepare to sacrifice themselves for the sake of their city – is deeply moving and, despite the odds, somehow very conclusive.

In what is really an ensemble piece rather than a vehicle for star singers, the cast is strong throughout. Soprano Paula Sides sang the fairly uninteresting part of Eleonora with a beautiful tone, and her pining for her husband Aurelio was well matched by Eddie Wade as Eustachio, mayor of Calais and Eleonora’s father-in-law. Eustachio is the real hero of the opera, being the first to offer himself up to the English, and Wade’s delivery was confident and effective, if not much more – he wasn’t helped by having to deliver numerous key declarations while seated on a bucket.

While Cozmin Sime (Eduardo III) and Adam Tunnicliffe (Edmundo) both impressed as the conniving English villains, the pick of the smaller roles was Andrew Glover as the burgher Giovanni d’Aire. Finding a slight extra sheen that eluded the other singers, Glover could perhaps have been the lead tenor that Naples apparently lacked in 1836 – why the lead role in this opera is a “pants role” for mezzo-soprano. Not that I mean to suggest that Helen Sherman was lacking as Aurelio, though – she caught the mood of this spirited and passionate young man to great effect, and clearly relished this virtuosic role, producing some striking singing. The standout moment – both vocally and dramatically – was the closing sextet, in which Eustachio, Aurelio and four burghers prepare for their imminent execution. This was a testament to the uniform strength of the singers – as well as to the production’s emotive clout.

It was, I should add, a little disconcerting at times to see such a grim story told to such rather bouncy music. While Donizetti does respond somewhat effectively to his subject matter, his default musical language can’t help but come across as slightly jarring today. If there’s one thing that can be said with any certainty about classical music since 1836, it’s that it has developed a very high number of compositional styles more suited to capturing the horrific realities of war than Donizetti’s.

But that said, if you are at all under the impression that bel canto opera is just about the singing (as, to be fair, the term suggests), then this is a production that you need to see. It’s also crucial viewing if you doubt the capacity of contemporary directors to maintain respect for the operas of past centuries while still doing all kinds of crazy things to the original document. Most of all, ETO’s The Siege of Calais is one to see if you enjoy compelling, well-realised operatic drama. Here’s to hoping that the opera (in this version) makes it to more opera stages in the future – but just in case it doesn’t, you’re advised to catch this now.