As Oreste started, I thought for a fleeting moment that I was in the wrong place. Had I gotten lost among the twisting alleyways of East London? Why was a mascara-streaked, hammer-wielding teenage girl butchering a hapless prisoner on stage?

Then the orchestra struck up the opening chords, and I realised that said girl was meant to be Ifigenia. In Handel’s original (though original is a bit of a misnomer, Oreste is a pastiche of music cobbled together from earlier works), Ifigenia is the unwilling priestess of Diana on the island of Tauris, forced to ritually sacrifice all those who land on King Toante’s shores. Her long-estranged brother Oreste, driven mad by the Furies for murdering his mother, wanders the world in search of relief and is washed up on Tauris. Ifigenia tries to help him escape from the island with the aid of Filotete – the captain of the guards who has fallen in love with her. This plan is complicated by the capture of Oreste’s wife Ermione, and his faithful friend Pilade who have come to Tauris in search of him.

Before I had quite recovered from the initial shock of seeing the temple of Diana represented by a slaughterhouse (complete with a generous splash of blood from the latest sacrificial victim), Oreste himself shuffled into view. Dressed in tatty pyjamas and picking vacantly at his shirt hem, he looked more an escapee from a mental asylum than the tortured “man of noble descent” that Ifigenia proclaimed him to be. But then he opened his mouth to sing, and what a contrast! On that gritty, graffiti-ridden stage, after the gore and horror of the opening scenes, Angela Simkin’s voice was unexpectedly beautiful.

The more I watched, the more mystified I became. Director Gerard Jones’ production of Oreste is intentionally ugly and stripped-down, devoid of the niceties of classicalism. There is nothing sacred about ritual sacrifice in Jones’ vision of Tauris – only madness and horror. I soon came to the conclusion that everyone was insane; except perhaps Pilade, a lone figure of normalcy in a cast of deranged characters.

Despite my preference for a classical style, the modernity of the production was not what perturbed me. As a Beckett-esque absurdist theatre unfolded on stage, the soaring notes and romantic lyrics seemed to be from a different production entirely. “O fairest eyes of my beloved… For you I shall suffer the joys and ills of Fate!” – How could I believe that, coming from a slavering Filotete who leered after Ifigenia at every opportunity? Jones might have been going for dissonance, but it just did not work.

Oreste is a long, three-act opera, and the ROH made the unfortunate decision to run the first two acts together. By the end of the second act, I had grown quite weary of the characters. Nothing made any sense. Vacuous, twitchy Oreste failed to inspire in me any admiration or reason to believe why the other characters were so willing to lay down their lives for him. When the reunited Oreste and Ermione sang their passionate “Ah mia cara” duet at each other with an utter lack of emotion, it was just too much. I closed my eyes. That certainly improved the performance; the lovely voices of Angela Simkin and Vlada Borovko carried me away. At least the denouement, with its final twist, managed to explain the peculiar actions of the characters in the first two acts – but the belated realisation that it was all intentional was too little, too late. Hilariously, Pilade gave up on the lunacy surrounding him, donned his lifejacket and slipped quietly away in the last scene. Presumably he was off to a saner island. Despite the somewhat misguided production, the talent of the singers managed to shine through. Oreste is the ROH’s annual production of the Jette Parker Young Artists programme, and there was no small amount of talent showcased on stage that night. Angela Simkin (Oreste) and Jennifer Davis (Ifigenia) stood out for me especially, accompanied by the very competent Southbank Sinfonia under conductor James Hendry.

If Gerard Jones is aiming to shock audiences with his postmodern production of Oreste, he certainly managed to do so. I’m not very sure what else he managed to achieve.