One of the downsides of having such a mammoth success with a musical that it runs for decades is that the original production tends to remain the production, rolled out internationally ad infinitum. Definitive is one thing, practically exclusive quite another. There have, of course, been the odd new stagings, often to accommodate different scales of venue – I once saw a downsized touring Miss Saigon (no helicopter) and, in Denmark, a somewhat bizarre rock-concert style Les Miserables. Sir Cameron Mackintosh, the producer of both of those shows as of Phantom of the Opera, once told me about a rather hair-raising Phantom staging somewhere abroad where UK health and safety regulations didn’t apply, and the chandelier fell at vertiginous, nerve-jangling speed.

But still, even these tend to be variations to some extent on the originals. And whereas in opera there is a healthy tradition of throwing some fascinating new lights on works with new, if sometimes deeply unusual stagings (imagine Phantom set in space – like a certain German Ring cycle I could mention), this is rare with what we might term the 1980’s juggernauts (Cats, Starlight Express, Phantom of the Opera, Les Miserables, Miss Saigon). So the announcement of a new 25th anniversary production of Les Mis, premiered in Cardiff and now brought to London’s Barbican Centre, where Trevor Nunn’s original started in 1985, was rather exciting. No Nunn, no John Napier sets, no on-stage turntable. Would this reveal something new about the old(ish) warhorse? Yes and no, is the answer.

The evening starts very encouragingly – where dedicated Les Mis fans have been raised (bear in mind I first saw the show when I was 11) to expect forlorn prisoners wielding pickaxes on a chain gang, the audience is now presented with the hot belly of a galley-ship, complete with anguished convicts at the oars, beaten by prowling, Claggart-like police. Thereafter, in place of backdrops there are projections, often and aptly of Victor Hugo’s own paintings – and sometimes the projections venture into the world of special effects, as with a superb sequence when they take us down into the Parisian sewers where the villainous Thenadier scavenges trinkets from the corpses of dead students. Yet directors Laurence Connor and James Powell never let the graphics overwhelm, and blend them brilliantly with traditional stage devices (best of all for one key moment, where a projected bridge, a few pieces of real set and a flying wire combine for an especially thrilling death scene).

All of that said, there are probably more similarities with the Nunn than there are differences. We still get the red flag flying over the crowd, the en masse marching in time during One Day More, the gates of Jean Valjean’s house look the same. So this is rarely a radical reimagining (though some sequences now work better, as with the depiction of the seedy, narrow alleyways where Valjean gets mugged).

Where it does score above all, though, is in new thought, new life given to the characters and their relationships. Valjean, as winningly played here by John Owen Jones, moves from a truly thuggish, bestialised ex-con (you wouldn’t want this chap anywhere near your house) to redeemed sinner. Earl Carpenter, like Owen Norris a veteran from the West End production, is an obsessive by-the-rules rather than demonic Javert. Katie Hall’s Cosette shows interesting touches of rebellion against her over-protective foster parent.

They pay attention to the smaller roles, too. In this incarnation, the drunk revolutionary Grantaire becomes a major figure, a disillusioned and despairing poet-cynic (a moving performance from Adam Linstead).

Most excitingly, the energy of a work re-explored pulses through the show. This first night felt like the first night. Every cast member threw themselves at their roles, occasionally to the point of over-doing things, but I was pinned to my seat. The new orchestrations, by Chris Jahnke, are more hit than miss and certainly it all sounds very now (though I could have done without the odd pop styling from Rosalind James’s feisty Eponine). They even had a bona fide UK charts star in the cast, Gareth Gates, as an earnest but slightly reedy-sounding Marius. Now – how about setting the next version in New York’s Little Italy (copyright applications to Dr J Miller, care of English National Opera, please)?