A conspiracy theorist might ponder whether the programming of William Tell during the final week of the 2014 Edinburgh International Festival, the day after the Salmond-Darling Scottish independence debate on the BBC, was intended as a propaganda move in support of the “yes” campaign.

Certainly the fervour of the opera's grand finale, as the Swiss rise up in triumphant revolt against their hated imperial overlords, is so palpably rousing as to make one at least question the commonplace assumption of Rossini's indifference to political matters. And in a coincidence sure to fuel our conspiracist's fantasies, the Milanese censor gave the green light for the opera's staging at La Scala – several years after its 1829 première in Paris – only on condition that the setting be changed to Scotland, with the protagonist restyled as "Guglielmo Vallace", and a name change from Gualtiero to "Kirkpatrick".

But even if one is left  to wonder who could, without ludicrous hyperbole, be figured as the dastardly tyrant Gessler in such a contemporary allegorical reading, an undeniable frisson vibrated through the audience gathered in Edinburgh's stately Usher Hall. Mixed therein were Scottish politicos and Italian diplomats, the Italian Embassy in London having supported the production “on the occasion of Italy's 2014 Presidency of the Council of the European Union” – a clue, perhaps, to the malleability of the opera's message in the eyes of the beholder. And what to make of the apparent plethora lately of productions of this otherwise rarely seen opera, with a new one to be unveiled next month in Cardiff?

And this without any staging, without the barest hint of Regie. Where innovative approaches to opera presented in “concert performance” are increasingly part of the landscape, the Teatro Regio Torino opted for the most traditional format, more staid even than an oratorio: there was no lighting, the singers at most walking on and offstage to indicate a change of scene. Subtitles were likewise lacking, but those with programmes in hand could follow the printed libretto.

Still, conductor Gianandrea Noseda led a spirited performance of enormous variety and sufficient colour to compensate for the lack of theatrics. No question, the Teatro Regio Torino Orchestra was on splendid form, the real protagonist of the evening, along with the chorus expertly rehearsed by Claudio Fenoglio. Already in the overture, Rossini's marvellous tone poem avant la lettre, Noseda made it clear that he wouldn't single out a particular aspect of this capacious score to favour, from its pastoral interludes to violent storms, its lyricism, or its blood-pumping, heroic momentum. Rather, all of these were present and fully delineated, in intriguing juxtaposition.

Noseda incisively shaped Rossini's many variants of lilting countryside rhythms, yet turned on a dime to whip up the martial frenzy when needed. There was symphonic heft, an almost Beethovenian muscularity, in the score's most powerful climaxes. The strings played with dashing ensemble clarity in the Act 4 storm sequence and the principal cellist and horn player made memorable contributions. The chorus, too, is essential not just as a supplier of Rossini's local colour but as a motive force in the drama; indeed it must assume multiple roles, representing different Swiss cantons, the oppressed people, and even the occupying soldiers who do Givernor Gessler's bidding. If anything,  they veered on being overbright at some points, but in general commanded a well-judged dynamic spectrum.

Presented here in the later Italian version, but with only a modest amount of cutting (such as the choral scene-setting at the beginning of the second act), Guglielmo Tell lasted just under four hours, including two intermissions and an introductory speech dedicating the performance to the late Claudio Abbado.

William Tell is notorious for being outrageously difficult to cast, and Torino had to accommodate several unanticipated changes. Curiously, the title role proved to be a weak link here, with Dalibor Jenis as a rather dull, uninflected superhero who is not only an expert marksman but a champion navigator and political alpha-male to boot. Admittedly, this isn't Rossini's most interesting music, and his characterisation of Gessler (given a disdainful, patrician-like demeanour by Luca Tittoto) is also relatively flat. Gessler's henchman Rodolfo, however, took on a more vividly menacing presence in Luca Casalin's colourful phrasing.

The first act in particular failed at several points, especially in the absence of staging, to overcome its static longueurs. Along with the orchestral and choral vignettes, the most successful musical characterisations arrived in the subplot of Arnoldo and his love for Matilde, a Habsburg princess who ends up rooting for the Swiss cause. The American tenor John Osborn was a casting triumph as Arnoldo, all but stealing the show in his magnificent "O muto asil" in the last act. Osborn navigated Rossini's impossibly difficult high tessitura as surely as Tell ferries about Lake Lucerne, but what truly thrilled was his sophisticated grasp of the character's complexities as set to music. Osborn provided fragile tenderness as well as  full-throated patriotism, capturing Arnoldo's desperate need to assauge his sense of guilt over the death of his father Melcthal, here sung with booming vigour rather than mere age by Fabrizio Beggi. His second act trio with Tell and Gualtiero (Mirco Palazzi in heroic voice) ranked among the highlights.

The romance with Matilde came off persuasively. As the brave princess, Angela Meade included tasteful ornamentation and delicate pianissimo phrasing as well as sensuous low notes, her huge voice securely powered if lacking somewhat in depth of expression. It made for a delightful contrast with Anna Maria Chiuri's earthy Edwige, and the intrepid young soprano characterisation by Marina Bucciarelli as their son Jemmy, on top of whose head Tell splits an apple with his arrow in Schiller's most iconic scene.

In Rossini's splendid apotheosis (which, in retrospect, turned out to be his farewell to the stage), the freshly optimistic Swiss join in an ode to liberty as the vehicle of joy, the chorus floating ever onward with a glowing serenity that almost hearkens ahead to Parsifal. Even in the native language of bel canto of this Italian version, Noseda and the ensemble conveyed a sense of the composer's forward-looking musical language, casting aside as it does so many of the familiar formulas of old, in which “a new world is revealed.”