Whatever musicologists may tell us about the patchy authenticity of Monteverdi’s last two operas, they unquestionably make a pair. Il ritorno di Ulisse is all about fidelity and ends with a love duet between the reunited husband and wife.

Bomb-dropping is the new black again in Trump's dysfunctional America. Awareness of that contributed to the crackling cloud of dynamic dread hanging over last night's concert staging of John Adams's opera-oratorio - my description, not his - about the July 1945 desert testing of the plutonium bomb under the supervision of self-divided Robert Oppenheimer, an American Faust.

"But is any of this normal?," asks poor Beatriz at the end of Act One. Of course not. She and 14 other grand creatures are crossing the space of an aristocratic drawing-room from which, they are coming to realise, there is no escape. At the same time, it’s completely normal. This is opera.

“Never give one concert if you can give a hundred” might stand as a motto for the conductor who once hauled his choir and orchestra round the world performing all 200 or so of Bach’s cantatas. And mathematically Sir John Eliot Gardiner’s latest project is a nearly exact honouring of that idea.

How well do you know your bad Victorian poetry? “When through the purple corridors the screaming scarlet Ibis flew/In terror, and a horrid dew dripped from the moaning Mandragores.” Go on, guess the author. Or how about this? “What time the poet hath hymned/The writhing maid, lithe-limbed,/Quivering on amaranthine asphodel". Got it yet? The first is Oscar Wilde’s The Sphinx, from 1881. The second, WS Gilbert’s libretto for Patience – written in the same year, and skewering Wilde with gleeful relish and lethal precision.

What to pair with Bluebeard’s Castle? It’s always a dilemma for opera companies. Something lightweight, even comic, provides contrast but also risks trivialising Bartók’s dark, symbolist drama. Something equally brooding risks submerging the audience into an evening of endless gloom.

"È un'immensa pietà" - "it's heartbreaking," rather than "it's a huge pity" - sings consul Sharpless of "Butterfly" Cio-Cio San's fatal belief that her American husband will return to her.

A wife dies to save her husband; a hero goes to hell and back to retrieve her from the underworld. Nothing of this dark myth, other than a rollicking row across the Styx from a bass singing Charon, ferryman of the dead, remains in Handel's incidental music to Alceste, a play on the subject by Tobias Smollett (of Roderick Random fame) which never reached a putatively extravagant Covent Garden staging and which has vanished from sight.

The annual London Handel Festival is dutifully working its way through every one of Handel’s operas in a cycle that will eventually take us from Alcina to Xerxes before, presumably, starting all over again. But each year, alongside these headliners, we also get a pasticcio – an opera stitched together by Handel from the shiniest and most decorative musical scraps by his European colleagues.

Isn’t it funny? You wait ages for an opera by an eleven-year-old and then two turn up at once. The world’s feature journalists descended on Vienna at Christmas for a new take on Cinderella by Alma Deutscher. What they heard, for what it’s worth, was a precocious, glittery pastiche of Classical manners. Last night was the real deal. Die Schuldigkeit des Ersten Gebots, by Mozart: "The Obligation to Keep the First Commandment". Not a title to make the heart beat faster, is it?