The London Handel Festival makes something of a speciality of digging deep into Handel's back catalogue to find things that even the seasoned enthusiast might not yet have heard, and Giove in Argo had, until this week, not been performed in London since 1739. Giove is the only one of Handel's 41 Italian operas which has come down to us without a complete original score: even as late as 1950, only the libretto and a few scraps of music were extant. However, John H. Roberts unearthed two missing Giove arias (not by Handel, but by Araja) in the Fitzwilliam Museum in Cambridge, inspiring him to reconstruct the opera, not least because Handel had largely simply plundered his own works (Faramondo, Alcina, Ezio and Imeneo) to set Lucchini's libretto. It was a case of cherchez le score, and Roberts has truffled up some gems for us, some familiar and some rare. The Royal College of Music, with an enthusiastic and talented student cast, gave Giove in Argo a dramatic rebirth at the Britten Theatre.

If anything, this rebirth was overpoweringly dramatic. Molly Einchcomb's design can best be summarised as an Alexander-McQueen-influenced dystopian vision of mythological Japan: you may already perceive how much there was to deal with visually. While the look was certainly exciting, and sleekly contemporary, the brutality of the setting could not have been more at odds with the ravishingly pastoral choral odes, and seemed to shout into the silence of the all-too-absent plot. I am an avowed fan of minimalism, of symbolism, indeed of many -isms in set design, but even I found it hard to understand (let alone believe) that the black-clad figures weaving through prickly telegraph poles were in fact hunters in a forest of minimalist trees, and often found myself resorting to checking the libretto in the dark to decipher the stage action. It was very cool, all beautifully executed, and presented with exceptional flair; a splendid act of imagination, once you had got used to it. However, for such an unfamiliar opera, a gentler setting might have been more helpful.

The story itself is not much help either. Lucchini's libretto is loosely based on two of Jupiter's amorous adventures from Ovid's Metamorphoses, seducing Io and Callisto, except that in Giove the seductions never take actually place, Io does not turn into a heifer, Callisto does not turn into a bear, and numerous other things that you might reasonably expect to happen, simply don't. Instead, Giove's adventures morph into an endless parade of nymphs and shepherds wandering in the green wood, not quite managing to be in love successfully, with Diana and her hunters relieving the romantic mood every now and again with a shot of bloodthirsty ecstasy; and every time anyone experiences any kind of emotion, usually woe, they get a long (and lovely) aria to tell us all about it. Director James Bonas gives all the characters plenty to do physically, which definitely enhanced the idea that something was happening: climbing the minimalist trees, hiding (very slightly) behind them, crawling in despair, fighting, and so on. Still, the plot moves very slowly, never gets far, and as the evening went on, it started to feel like a long one.

The consolation was, as always at the Royal College of Music, the opportunity to see some really exciting young singers, and this evening we were dazzled by potential. Top of my list has to be Angela Simkin, who shone as Iside (Io, also the Egyptian goddess Isis, wife of Osiris) from start to finish. From her first entrance (crawling), Simkin's luscious and liquid soprano thrilled the audience, her intonation crisp and clear, her acting polished. Unknowingly confronting Giove (Peter Aisher), Simkin turned the tables on the king of the gods, immediately assuming the power of the erotic encounter and ordering him about with hilarious impunity in “Taci, e spera”; later, confronted by her husband Osiri (Nicholas Morton), Simkin transformed smoothly into a deferential, anxious, desperate wife eager to repair her marriage.

Sofia Larsson also gave a stunning performance as the virginal nymph Calisto, singing with wonderful purity and strength, though why it had been decided that she had to first appear on stage looking as if she had just been let out of a pigeon loft I couldn't quite fathom. Larsson's sense of genuine excitement at being accepted as one of Diana's virgin huntresses was excellent, as was her tremblingly hesitant acceptance of Arete (Giove in disguise) as her lover. Larsson's “Gia sai che l'usignol” was just one lovely moment in a performance filled with fluency and grace; “Ah! non son io che parlo” was another highlight. Peter Aisher, as Arete, had a natural stage magnetism which worked brilliantly for his Puck-like Jove, superbly articulate in all his physical gestures and utterly focused, singing “Semplicetto! a donna credi?” with vivid humour. In Aisher's playful, irresponsible and powerful Arete, I could also see a credible Jove; not so far, perhaps, from the relationship between the Wanderer and Wotan, another king of gods who knows the impulse to 'get away from it all', though it must be said the Wanderer has rather nobler philosophical aims.

The most exciting transformation of the evening came from Nicholas Morton's Osiri, who arrived little more than a Boy Scout, but finished very much a god, Morton singing throughout with depth and strength, particularly good when furious with Iside. Rose Setten gave a visually striking performance as Diana, complete with horns and towering crest, presiding over a wonderful ritual killing scene in Act I. Setten did not always sound quite as comfortable with this music as her companions, but created a thoroughly believable and memorable goddess. Matthew Buswell was a suitably squirming Licaone, the token bad king whom Iside has come to the forest to kill (and eventually does).

The chorus was fabulous throughout, each member characterising their own unique part but also working smartly together: as ever with Handel, the choruses are all treats in their own right. Laurence Cummings conjured a warm and engaging sound from the London Handel Orchestra, led by Adrian Butterfield. Altogether, it was impossible not to enjoy the sheer musicality and talent before us, and John H. Roberts has put together an exquisite confection of sounds to indulge the Handel fan, who will have fun spotting the original sources of each aria. However, for Handel or opera newcomers, Giove in Argo would not be the best of introductions to the great man or his art form.