When you go to a trendy London performance "space" to watch an opera about rape and murder you should probably expect a few shocks. Or, if this ain’t your first Don Giovanni, you should expect not to be surprised by whatever provocations the director may have in store – which is much the same. What you probably don’t expect is for the overture to be played electronically and/or sound like it’s been remixed by Thom Yorke. But in Robin Norton-Hale’s "new version", that’s what you get – and plenty more besides. And you know what? It really works. It does. Mostly.

What was the audience on? They tittered when the bicycles came on, nearly cried when the whip was unleashed and virtually pissed themselves when the warring sides in Handel's crusader fantasy Rinaldo started fighting it out with hockey and lacrosse sticks (I know! Too-oo funny!). After last year's randy bunnies, Glyndebourne's Prom visits are fast becoming the nights to bury bad comedy.

We critics often find ourselves "embarrassed by historical facts", as Craig Raine once put it. Raine was trying to explain why so many people still value Wilfred Owen's poetry - to him, the most overrated corpus of the 20th century. "[Owen's] life and death as a soldier make literary criticism seem invalid and pedantic," he argued, before proceeding to a very validly pedantic demolition job. Music has its own Wilfred Owens. Viktor Ullmann is one. His reputation (which was showcased last night in a rare staging of his only opera, The Emperor of Atlantis, at the Arcola Theatre) seems to survive solely on the back of his death at Auschwitz. It's a good reason to honour his memory, but not a good reason - alone - to listen to his music.

Glyndebourne’s production of Benjamin Britten’s terrifying The Turn of the Screw is one that really does turn the screw tightly in the mind. It pierces time with its updating from its original Victorian setting to a bleak Fifties Britain, it tightens the tension with its wintry, claustrophic setting, and it delivers its questions into our suspicious, information-saturated modern heads with added twists. Given a magnificent musical and dramatic ensemble to interpret it in this revival, it's an evocative way for Glyndebourne to end this tense, unpredictable summer, art gnawing away at the stable certainties of British classical culture.

In 1981, when I last came to Bayreuth, the festival still seemed to be a battleground between the German Left and Right, between the blame faction and the guilt faction, between the commie East and the fat-cat West. Plus ça change. Without quite openly taking sides, Sebastian Baumgarten’s new staging of Tannhäuser rings some cracked old political bells while, apparently with Bayreuth’s connivance, candidly parodying most of the thinking that underpins this admittedly somewhat raw, yet for Wagner absolutely crucial early work.

Vignette Productions is a bit of a one-off in the operatic world. It was established three years ago by the rising young British tenor Andrew Staples, his mission to create operas that were more exciting and told better stories than those generally on offer. Staples directs rather than sings; his casts are made up of young unknown singers, and the productions to date certainly fulfil the original aim. Last year, their summer production of Cosi fan tutte had the audience sitting in deckchairs atop of six tons of sand and ended with a beach party. With that in mind, a bit of youthful wackiness was absolutely to be expected, nay joyfully anticipated, from La bohème this week. Wacky it was too, and in a very good way.

Longborough has its Mozart (this season a not wildly exciting Così fan tutte), and it has its Verdi (this year Falstaff). But its real heart is in Wagner, and in particular The Ring, now – in its third year – up to Siegfried. Wagnerites infest the car parks and the picnic lawns. The man who borrowed our corkscrew at supper time had seen six operas in one week at Bayreuth, and on his one night off had gone to Munich to see Rienzi, the longest Wagner night of the lot. Longborough is decidedly his kind of place.

The Hallé Orchestra, enlarged for the occasion with harps, anvils, horns and such, was in its place on the platform. Sir Mark Elder made his entrance like a surgeon about to embark on a complex and energy-draining heart bypass operation. And the lights went out. On purpose. A spotlight picked up a man in a white shirt with long hair mounting the platform and making his way to a small table, chair and reading lamp mid-stage. It was Richard Wagner – in the form of actor Roger Allam. Pure melodrama.