Götterdämmerung; BBC Proms – review

The idea that you can drive down a lane or up a wold, park in a field then have an operatic experience comparable with the best still feels miraculous. UK operagoers should be used to this kind of thing, given our appetite for bucolic summer revels. Not a bit. This week an outstanding Götterdämmerung – the fourth and last opera in Wagner's Ring cycle – in the Gloucestershire village of Longborough was the latest to have us rubbing our eyes and ears in disbelief. By any reckoning it was a staggering achievement. Lest you assume this is mere journalistic excess, I am contemplating returning for more.

Offering uniformly excellent singing of an intelligence and musicality too rarely encountered in international houses, this shoestring staging challenges notions of professionalism. It forces us to ask how this little festival, privately run on a precarious budget and with no major sponsor, can muster performances of this quality and intensity. Yes, the production (by Alan Privett) relies on minimal props, inventive lighting and a handful of bold but uncomplicated visual ideas. The impromptu orchestra of around 70 is big enough for the 500-seat auditorium – a comfortable, purpose-built theatre on the site of a former chicken barn and with a witty facade which mimics the Wagner shrine of Bayreuth.

The orchestral sound is not always refined or absolutely precise. Yet the drama burns white-hot, every role taken with conviction, the terrible truths contained in Wagner's score communicated in vivid detail: Brünnhilde's doughty wisdom floored by betrayal, Hagen's depressive self-loathing, Siegfried's big-hearted exuberance withering to treachery. Never has Twilight of the Gods seemed so sharp and clear. Flow and pace are handled with easy authority by the conductor, Anthony Negus, who steers this operatic colossus as if it were a bird on the wing.

Kjell Torriset's designs are more or less modern, dominated by an altar-like disc, some nautical-style roping and three giant obelisk-like frames on which the Norns are wheeled. Waltraute (Alison Kettlewell), with a mane of Bonnie Tyler hair and the glamour of a Hollywood eco-warrior, issued her sisterly warning to Brünnhilde with compelling urgency. The Gibichung family displays ghastly nouveau pretensions. Poor Gutrune, abused and tricked, was sympathetically taken by Lee Bisset. Hagen, dishy as villains go, looks edgy and controlling in short coat and drainpipe trousers; Stuart Pendred sang with unexpected but convincing lyricism. It is no surprise to find that he started out as an actor and frequently charmed the crowds as the "official voice" of Chelsea football club.

An interesting twist was the handling of Hagen's thuggish and vain half-brother Gunther, sharply sung and characterised by Eddie Wade. This coward in yellow tie and ginger suit spins on stage in a wheelchair, at once passive yet muscle-flexingly aggressive. Then, as if restored to manhood by his false betrothal to Brünnhilde, he leaps up and pushes the wheelchair away for good. The implication, wholly convincing, is that Gunther seeks attention by faking a disability he does not suffer.

Longborough has found a magnificent Brünnhilde in Rachel Nicholls, a singer so versatile that she has also had a career as a Bach specialist. Full-toned, flexible, accurate and powerful, every gesture, every flinch is persuasive. Mati Turi's Siegfried, bear-like and yet subtle in expression, matches up superbly, his vocal heroics enduring to the moment of death. The chorus of playboy vassals, in crumpled suits and bare feet as if woken from hangovers, their spears more like snooker cues, were well drilled and powerful, though just a dozen strong. Yes, this is a small house, and some of these voices would have struggled at Bayreuth or the Met, but this is a specious argument: we were at Longborough and it worked.

As Martin Graham, co-founder of the festival with his wife, Lizzie, recalled after Tuesday's majestic first night, there was some mirth when their enterprise began back in the 1990s. Early on they staged a mini-Ring (in Jonathan Dove's reduced version) but always had dreams of doing the real thing. In 2013, Wagner bicentenary year, they plan three complete Ring cycles. They have not yet raised the money but Nicholls, Pendred, Bisset and Wade are confirmed in their roles. Seats range from £60 to £175 per opera. Book now, sponsor a spear (£25) or a horn (£75), and make this happen. This act of artistic philanthropy is as visionary and awe-inspiring as it is eccentric.

The new BBC Proms season exploded into life with a short, spirited, crunchy fanfare, Canon Fever by Mark-Anthony Turnage, commissioned by BBC Music magazine for its 20th birthday and performed by members of the BBC Symphony Orchestra. It added a welcome tang to the sweet, lambent glow of Britishness that followed: Elgar, Tippett and, the musical highlight, Delius's Sea Drift, its impressionistic colours sensitively captured by the BBC Symphony Chorus, with Bryn Terfel in towering voice as soloist.

Edward Gardner, Roger Norrington, Mark Elder and Martyn Brabbins shared the conducting. Yes, they "passed the baton", if you insist, and yes, it was an Olympics homage – a cheerfully bizarre opener but allowable in this oddest of years, and worth it to see Sarah Connolly, one of the soloists in Elgar's deathless Coronation Ode, wearing a fantastic, non-union flag Vivienne Westwood gown. I hope not to hear Tippett's perky Suite for the Birthday of Prince Charles (1948) again until its dedicatee celebrates his own diamond jubilee or the Olympics return to London, whichever is the later.

As part of the opening weekend, John Eliot Gardiner conducted a spellbinding, period-instrument reading of Debussy's Pelléas et Mélisande (heard on Radio 3) with a powerful cast and corruscating playing from the Orchestre Révolutionnaire et Romantique. Opera broadcasts often seem to favour voices, but here all was audible – essential in this score.

A surprise treat was Prom 6, on paper a standard concert-and-symphony affair. The BBC Symphony Orchestra, this time under conductor designate Sakari Oramo, gave the premiere of Fung Lam's Endless Forms, a pretty enough, episodic work inspired by Darwin's On the Origin of Species, with nice detail, if its entire evolution remained elusive. Rachmaninov's Piano Concerto No 2, with the Russian Kirill Gerstein as soloist, was poetic and impassioned, with a verve which carried through to Prokofiev's awkward and restless Symphony No 6. The BBCSO has upped its game thrillingly for its Finnish conductor-in-waiting.

Gerstein, meanwhile, a performer of finesse and restraint who kept a tight rein on the Rachmaninov, delighted the audience with an encore of one of Earl Wild's 7 Virtuoso Etudes on Themes of Gershwin. After some technical wizardry and having resisted piano-bashing all evening, Gerstein thumped the keyboard with his entire right forearm for a splashy final chord – the kind of thing every aspiring pianist can try at home.