We are sitting on stone steps in the semi-circular arc of the ancient Roman Theatre at Orange, staring at the monumental Roman wall in front of us. The set decoration consists of fragments of a broken mirror which would be giant in any other setting but looks tiny here. It’s topped with the Lion of St Mark, indicating that the opera that we are about to see is Verdi’s Otello. The stage fills with silver-grey clad chorus. Night falls.

Myung Whun Chung enters from one side. He steps onto the podium, and in an instant, we are left gasping as a thunderstorm of epic proportions is unleashed – not, it must be said, quite as epic as the real life thunderstorm yesterday, which caused the postponement of this performance, unprecedented according to the frequent visitors we spoke to – but Chung’s orchestral version ran it close.

The whole orchestral performance, from Chung and the Orchestre Philharmonique de Radio France, was simply sensational, with a rare combination of precision and high energy. Each part of the orchestra excelled: individual woodwind phrases came through with elegance and utter clarity, the string sound nuanced and perfectly together, the brass vibrant and the percussion thunderous.

The venue’s acoustics must have been partly responsible: such is the ancient magic of the Roman theatre construction, cut into the hillside, that individual instruments were audible in every detail in a way that you just don’t normally get at outdoor venues (or, indeed, most indoor ones). But the acoustic was kinder to the orchestra than to the singers, all of whom struggled to some extent to make themselves heard.

In the title role, Roberto Alagna was the one singer who managed consistently not just to be heard, but to impose his vocal presence above the orchestra. Alagna was magnetic, drawing eyes and ears to him as he veered between authority in his opening “Esultate”, tenderness in the lovely duet with Desdemona “Già nella notte densa” and near-insane brutality in the repetition of the word “Il fazzoletto” (the handkerchief) and the murder scene. His voice was clear and powerful – although even he cracked a couple of notes under the strain. Inva Mula’s Desdemona was sweetly sung and achieved the necessary power level, but at the expense of diction, with barely a consonant audible.

Seng-Hyoun Ko was a highly watchable Iago, turning in an accomplished acting performance. It’s Jago who pulls the strings throughout the opera, and Ko was compelling in portraying him as a tireless and efficient manipulator. But Iago’s big moment in Otello is his Act II “Credo in un dio crudel” (I believe in a cruel God), where he announces his intentions and expounds a “creed” of utter nihilism. The aria calls for a transition from scheming rogue into a spirit of undiluted, evil malevolence, and Ko didn’t succeed in making that transition.

I generally enjoyed Nadine Duffaut’s direction and staging. The giant shards of mirror apart, Emmanuelle Favre’s sets were relatively sparse. Direction of the very large chorus – or rather three choruses, from Avignon, Lyon and Marseille – was impressive, although it’s not necessarily a great idea to have everyone in motion during dialogue on a stage where the clumping of feet is loud and the singers are having enough trouble with volume already. But the best part of the staging was Katia Duflot’s 14th century costumes: silver grey for everyone except pure white for Desdemona and blood red for Otello, everything created in exquisite detail.

Coming to see an opera at an open air festival such as Les Chorégies d’Orange, I expected something of a spectacle, and that’s indeed what we got. But I really hadn’t expected an orchestral performance of the highest quality, allied to vocal performances which got stronger through the evening. The closing scene, with overpowering anguish from Sophie Pondjiclis as Emilia and Alagna’s searingly intense rendering of “Niun mi tema,” was soul-searingly tragic. And that, after all, is what Verdi and Boito’s rendering of Shakespeare’s genius is all about.