Forget opera-glasses, the must-have accessory for the contemporary opera-goer in London is fast becoming a sturdy pair of wellingtons. No sooner had we all dried off from our voyage into The Heart of Darkness at the Royal Opera House (where Edward Dick’s watery set lapped dangerously close to the orchestra pit) than we find ourselves up to our knees in the boggy marshlands and treacherous pools of Sam Brown’s Jakob Lenz.

Is it my imagination, or are we getting more Wagner in concert than we used to? It could be a welcome development. How marvellous not to have to tremble at the thought of the latest flight of directorial fantasy: Isolde pregnant, Siegfried as an airline pilot, the Grail temple transformed into the Reichstag (no prizes for guessing which of these is a real case). Instead you can enjoy what Stravinsky called “the great art of Wagner from the direct source of that greatness and not through the medium of pygmies swarming around the stage”.

David McVicar’s Rigoletto hurls full-frontal nudity and an orgy at the audience within its opening minutes – dramatic grenades to clear the well-worn ground ahead. Back in 2001 this may have been enough to shock-and-awe, but a decade and a couple of revivals on and it takes rather more. And more we certainly get in the current revival. Not only does Italian superstar tenor Vittorio Grigolo take his turn in the Duke’s tight britches, but John Eliot Gardiner takes charge in the pit for this, his first Rigoletto.

No greater proof of the potency of the current Handel revival can be found than the London Handel Festival, now in its 35^th year. The festival continues to fill concert halls and churches across London every Spring with the composer’s chamber repertoire, but it is the annual opera that remains unquestionably the main event.

I find it hard to square what I know about composer Judith Weir with what happened last night. In one corner lies her 30-year output of songs, choral pieces and operas - as engaging and beguiling an oeuvre as that of any living composer's. I think of her waggish song cycle King Harald's Saga or her playful opera A Night at the Chinese Opera.

Love it or hate it Christopher Alden’s A Midsummer Night’s Dream at English National Opera last year made quite the impact, banishing any fey woodland glades and general waftiness from Benjamin Britten’s opera and embracing a rather more astringent visual aesthetic. It’s unfortunate then that Martin Lloyd-Evans’s production for the Guildhall School of Music and Drama should follow so closely behind, begging comparisons that don’t best serve his World War II interpretation.

Why has the Royal Opera not staged Dvořák’s Rusalka before now? I know there have been plausible distractions: the lock grip of Italian repertoire, fear of singing Czech, fixation with Dvořák as an instrumental composer, two world wars, a shortage of good water nymphs. But Sadler’s Wells gave the British premiere of this musically sumptuous "lyric fairytale" (its official description) as long ago as 1959.

In October 1985 four Palestinian terrorists boarded the Achille Lauro cruise liner, took the 400-odd passengers hostage, shot an old disabled American Jew dead and flung his body overboard. Of all the many atrocities in the long war between the Palestinians and Israelis the murder of Leon Klinghoffer has always struck me as being one of the more morally cut and dried incidents. Hardly worthy of any kind of lengthy debate, let alone dramatic exposition.

To Charles Rosen it was a work of "rarely redeemed dullness". The wife of Emperor Leopold called it "German rubbish". It's pretty obvious why so many have objected to Mozart's final opera La clemenza di Tito. Tunes (memorable ones) are by and large lacking, which is odd for Mozart. The overture is not something you'd want to hear on its own. And the work's great solo arias are unwieldy in form (though fascinatingly so) and tricky to sing and separated by the vast wastes of a notorious recitative.

Such a pity about Beatrice and Benedict! As a musical visualiser, a creator of musical tableaux, a radio composer avant la lettre, Berlioz had few equals. The Damnation of Faust is surely the greatest radio opera ever written. But for some reason he had no grasp of the stage. Benvenuto Cellini is a lifeless succession of spectacular tableaux. The Trojans must have more superb music per square yard of ineffective drama than any work of comparable length.