Owen Wingrave is the Britten opera that always comes with a caveat, an apology. Dramatically flawed (a problem partially, but by no means entirely, accounted for by its genesis as a television opera) and musically uneven, it has nevertheless emerged recently as a favourite choice for young singers, with Guildhall (2013), the Royal Conservatoire of Scotland (2016) and now British Youth Opera (2016) all choosing to stage it, with varying degrees of success.

Between the Berlin Philharmonic, Leipzig Gewandhaus Orchestra and Simón Bolivar Symphony Orchestra it has been a big week at the Proms, in every sense. Scope and scale have been the watchwords for the orchestral tectonics that have taken place, the sonic landscapes that have been formed and reformed. But concert-goers on Sunday night were hit with an operatic aftershock of overwhelming force, bringing this penultimate Proms week to a close next weekend’s patriotic spectacular will struggle to match.

Karel Čapek, the great Czech writer who pioneered some of the most prophetic dramatic fantasies of the early 20th century, thought Janáček was nuts to want to set his wordy play about a 337-year-old woman to music. He could not have anticipated what that septuagenarian genius would achieve. Some of us felt similarly doubtful about singers performing this most conversational of operas with scores and music stands in a "concert staging".

Britten’s A Midsummer Night’s Dream is too other-worldly to have anything as mortal as a musical heartbeat. Pulsing through it instead are musical quivers, jolts of eerie energy first heard in the opening cello glissandi. Denaturing the instrument, transforming it from a voice so nearly human to one of harmonic and textural androgyny, Britten cuts away the safety cables of Shakespeare’s framing court scenes, plunging his young lovers straight into the fairy forest where anything is possible and nothing is as it seems.

"Because the world has outlived its own downfall, it nevertheless needs art." Paul Celan's words stand alongside Anselm Kiefer's Jacob's Dream, part of a stunning Surrealism-centric exhibition in the foyer of Salzburg's second and more amenable festival venue, the Haus für Mozart. What a meaningful motto it turned out to be for both of this year's major festival offerings, good and bad.

By the end of Act One of The Yeomen of the Guard there's been a jailbreak, a clandestine marriage, a swapped identity and a cancelled beheading. The chorus sings, halberds are brandished, and a jester jests. Even by Gilbert and Sullivan standards, it’s one heck of a tangle. And then, in John Savournin’s touring production, the stage clears and, true to Gilbert’s directions, Elsie faints in Fairfax’s arms while silhouetted behind them, masked and motionless, stands the grim figure of the executioner.

What happened was this. I found my way, not without difficulty, to the Barry Memo Arts Centre, got my ticket, had a chat with the librettist, stopped to order an interval drink, then turned round to discover that the entire audience had disappeared, as if eliminated by a Star Wars de-atomiser, or whatever those things are called. Two or three of us ran outside, looked this way and that, and after a few panic-stricken minutes tracked down the audience, who had gone right round the building in a crocodile and re-entered it by a door on the far side.

Locations count for little in most of Shakespeare's comedies. Only a literal-minded director would, for instance, insist on Messina, Sicily as the setting for Much Ado About Nothing. In Béatrice et Bénédict, on the other hand, Berlioz injects his very odd Bardolatry with lashings of the southern Italian light and atmosphere he loved so much. So turning it all grey as Laurent Pelly does and putting everyone into boxes except the loving enemies who think outside them - get it? - goes against the grain.

It's not often you think you detect a future Brünnhilde in a soprano performing a great Verdi role, but that was the case when American Tamara Wilson made her UK debut last autumn as a stunning Leonora in the ENO production of Verdi's The Force of Destiny. So would she sing the Ring? Not for 10 years at least, she said. But then Mark Wigglesworth, a conductor she knew she could trust as partner, proposed the final scene of Die Walküre at the Proms, and the rest should go down in history.

It’s the kitchen of a Thai-Chinese-Vietnamese fast food restaurant. The onstage orchestra wear sweatbands and T-shirts, and a red work surface stretches across the stage. As the four chefs take the stage, the clatter of pans and knives is first noise, then a rhythm, then an overture of sizzling, clanging, chopping and hissing sounds that spreads throughout the whole orchestra. Vegetables are sliced, pans brandished and, sitting out front, as an escaped slice of courgette rolls wonkily downstage, is a young Chinese cook, wailing with toothache.