Has there ever been a better time for a British lover of Bellini? Hot on the heels of English National Opera’s production of Norma only a few months ago comes this production at the Edinburgh International Festival from Salzburg, and if two Normas weren’t enough, the Royal Opera House opens its new season with a third production in September. A well-worn phrase relating to buses springs to mind, but what is delightful about this trio is that they are so very different. The Royal Opera’s production under Pappano promises to be Bellini at his traditional best, with a splendid soprano taking on the title role, while ENO’s had the English factor. This production at Edinburgh, though, will surely emerge as the most interesting.

There are few singers who can say that they have totally re-defined an opera, but Cecilia Bartoli has done managed it with Norma. She asserts that her restoration of a mezzo Norma to a soprano Adalgisa corrects a well-established performance error that came to define bel canto over the last seventy years; one of the defining earworms of the 20th century is, after all, Callas singing “Casta diva”. Her case is debatable, depending on how you categorise Bellini’s original Norma, Giuditta Pasta, but it’s an interpretation worth savouring. Bartoli insists on using a new critical edition produced by Maurizio Blondi and Riccardi Minasi, which has fewer cuts than has become traditional and a beefier role for Adalgisa, along with period instruments to try to recreate a more authentic Bellini sound.

Moshe Leiser and Patrice Caurier update this production to 1940s France during the occupation – the Gauls and Druids become La Résistance and their sacred place becomes a school; the performance begins not with the pounding overture, but with a bell and the sound of children and bells. It’s a powerful updating which successfully opens up Bellini’s full dramatic potential. The directors have a taste for small, but vivid moments of flair, noticeably the loud and brutal snipping of Norma’s luscious locks as she waits on the pyre, replicating the shaving of women that were accused of collaborating with the Nazis.

Cecilia Bartoli’s Norma is sensational. There is no other way to put it. Her absolute and total immersion is gripping, almost frightening to watch, the brutality of Pollione’s betrayal rippling through her face, a frenzied madness glinting in those soulful eyes. Her performance has intense physicality to it: collapsed on stage as the first act ends and the second begins, there’s palpable feeling of shattered bereavement; in “Vanne si mi lascia indegno” she is physically striking at Pollione and by God, the way she sings “Son io”, right in Pollione’s face, jabbing at her chest to show him her sacrifice, is utterly compelling. Vocally, though I miss Callas, Sutherland etc., Bartoli’s mezzo sounds intrinsically right in the role. Slightly thinning at the top as you would expect, the flexibility and classic Bartoli ornamentation is undimmed; the size of the voice remains a marginal difficulty when singing against the combined forces of the cast, chorus and orchestra, but it’s at its best in “Casta diva” - delicate, yet authoritative, sombre yet emotional. Her duets with Adalgisa were painted with the same colours.

Just about preventing Bartoli from carrying off the show as her own was Rebeca Olvera’s Adalgisa. I haven’t heard Olvera sing before, and I’m now very keen to see her again; her voice bubbles with a crystal clarity, pure and smooth at the top and beautifully articulated. Her soprano isn’t the most obvious choice for Adalgisa, but its freshness and unusual youthfulness made a good vocal (and dramatic) contrast with Bartoli’s more mature mezzo.

John Osborn’s randy Pollione was eager to strip for Adalgisa, but gave us a luxuriant performance, stirring up his treacle-dark tenor to some easy and elegant high notes. The refinement of the voice perhaps lacks the treacherous grit that some Polliones have (possibly prompting slightly hammy acting), though it was deployed with a seductive smoothness to get Adalgisa into bed. Péter Kálmán’s Oroveso was particularly moving at the end as Norma begged him to protect her children, but in many of his scenes, his voice lacked the grave authority best suited to the role and he struggled to make himself distinguishable over the chorus at times.

The Swiss Radio and Television Chorus were somewhat reduced in number to accommodate the general downscaling of the production, but sang melodiously enough, though the acting was often somewhat static. Their chorus master Gianluca Capuano stepped in at very short notice to replace the indisposed Diego Fasolis conducting period ensemble I Barocchisti; the slight disruption was occasionally audible in the brass and woodwind.

This was very much a vehicle for Bartoli and she delivered in a thrilling performance of vocal and dramatic virtuosity.