Nothing says summer opera quite like the skittish melodies and Neapolitan oom-pah-pah of a Donizetti overture. It doesn’t get much cheekier or more playful than this, the kind of music that makes you long for a pea shooter to pelt opera-goers with a stealthy fire of peanuts, or daub the bald head of the concert-goer in front of you during his Act II siesta. When set against the greenery and obbligato peacocks of Holland Park, a work like Don Pasquale makes sense in a way it scarcely can in the corseted confines of a traditional opera house. Add a witty staging by Stephen Barlow, and Richard Bonynge – the godfather of bel canto – in the pit, and summer sunshine is guaranteed, whatever the weather.

Tosca-at-Covent-Garden is a commodity, like bacon-for-breakfast - a pricier commodity, to be true, at officially up to £229.50 a seat, but in both cases people want to get what they expect. For the final performances next month in this summer revival, with the megastars Angela Gheorghiu, Jonas Kaufmann and Bryn Terfel, all seats are sold, with touts on eBay offering a pair of amphitheatre seats at bids over £300.

They say that old sins cast long shadows, but these are nothing compared to the shadows cast by old productions. To set Verdi’s Rigoletto in 1950s America inevitably courts comparison with that operatic patriarch, Jonathan Miller’s New York Mafia reworking.

Tamino and Pamina, in Mozart’s great masonic opera, go through fire and water, as well as trials spiritual and emotional, before achieving their sunlit triumph at the end of it all. They would have sympathy with Anthony Whitworth-Jones and his Garsington Opera team in what must have been quite as frightening a battle to locate, plan, design and build their new pavilion on the Getty estate at Wormsley, near Stokenchurch on the M40, within barely more than a year.

No point in going to WNO’s Turandot expecting to see images of old Beijing, for all the charming lady in a Chinese floral hat on the programme cover. The curtain goes up on the inside of an enormous galvanised dustbin festooned with photos of what might be lads from the football team but are actually Turandot’s victims to date. Calaf is a vagrant, Turandot a blue-suited Rosa Klebb, Ping, Pang and Pong fascisti bureaucrats in coloured suits, the “Popolo di Pekino” (both sexes) shirted and tied office workers, and so forth. Perfumes of the East? Forget it.

The staging smacks of Covent Garden's familiar Verdi-by-numbers - surprising since it's the often inventive Phyllida Lloyd's concept, revived by Harry Fehr, but it might as well be the inert pageantry of Elijah Moshinsky - while the necessary singing-acting, no doubt as a result, is mostly one-dimensional and overcooked. Verdi's first confident shot at music-theatre, revised for Paris in 1864 but already vivid in outline four years before Rigoletto broke the mould, deserves better. At least it enjoys firm-of-purpose conducting by Antonio Pappano and one vocal performance of unflagging brilliance.

Two 1950s Mozarts in one weekend might seem like pressing the contemporaneity of great art unnecessarily far. But Jonathan Kent’s Glyndebourne Don Giovanni, revived on Sunday, is a much less crude update than the WNO Così.

So the world didn't end yesterday as predicted, and Wagner's divine comedy about the meaning of art has weathered the ironic apocalypse following Hitler’s misappropriation. Bayreuth reels, but we Brits are lucky to have two stagings in under a year which take the humanism at face value. Scaling it down for Glyndebourne's intimate summer paradise, given director David McVicar’s knack of finding a plausible historical setting, should have offered a viable alternative to Richard Jones's hallucinogenically wonderful Welsh National Opera production. Often it did. The problem was that several singers were a size or two too small, one way or another, for the shoes cobbled by master craftsman Wagner.