In the end, it’s all about the oranges. They adorn the programme that accompanies Harry Fehr’s intelligent new production of Handel’s Ariodante for Scottish Opera. More importantly, they’re prominent in designer Yannis Thavoris’s clinical steel-and-glass set, growing on carefully groomed bushes in six neat tubs, placed meticulously below warming light bulbs, protected from the gales and snow drifts outside by a wall of glass.

In the light of what follows, it's probably best to be clear that I'm completely behind the artistic side of ENO in rejecting a 25 per cent reduction of the chorus's annual salary, tied to a shorter season. A full-time chorus of this size is the heart of a big company – without it, no Mastersingers, no Grimes, no Lady Macbeth of Mtsensk. A creative alternative solution must be found.

Spoiler Alert. It’s Act Three of Purcell’s Dido and Aeneas. The witches have done their worst, Aeneas is about to take ship, and the tenor Guy Simcock steps forward as the drunken sailor to sing what – as music director Christopher Monks has confided to us before the overture – will be his first solo role with Armonico Consort. At which point, the leader of the orchestra suddenly leaps up onto a chair behind him and starts belting out the sailor’s song himself, reeling tipsily about and fiddling all the while as Simcock slumps disconsolately back to the chorus.

The latest themed season from WNO, to add to their fallen women, Donizetti queens and what not, goes by the slightly worrying title (for anyone with a short attention span) of “Figaro Forever”, and consists of an operatic sequence derived from Beaumarchais’ three Figaro plays and ending with a new opera by Elena Langer partly based on the last of them, La mère coupable.

“We are at a time of present crisis.” When Sarastro addressed his boardroom of business-suited acolytes last night, there can’t have been many in the Coliseum whose thoughts didn’t turn to English National Opera. Even by the standards of a company that has spent most of its history fighting for survival, 2015 was a year of unprecedented difficulty. Whether crisis becomes catastrophe remains to be seen, but there couldn’t be a more emphatic portent of success, a better-timed metaphor, than this Magic Flute.

"I wish I had money," exclaims the weak-willed hero of Stravinsky's The Rake's Progress and, hey presto, the devil appears to strike a deal. Auden and Kallman didn't have the last word on Faustian-pact librettos. Now writer Louise Welsh and composer Stuart MacRae, successful collaborators already on the award-winning Ghost Patrol, have had the bright idea of turning a fiendishly clever short story by Robert Louis Stevenson, The Bottle Imp, into an updated operatic subject.

Why have all attempts to make French comic opera funny to British audiences fallen so flat, at least since ENO's 1980s Orpheus in the Underworld? That company's La belle Hélène simply curled the toes, while Opera North managed to make a pig's-ear "special edition" of Chabrier's Le roi malgré lui. L'Étoile in its first staging at the Royal Opera fares better, not least because it's mostly performed in impeccable French, but does it ever reach the potentially hilarious pitch of Gilbert and Sullivan?

Unlike Schubert, Mendelssohn and Shostakovich, Mozart composed nothing astoundingly individual before the age of 20. That leaves any odyssey through his oeuvre, year by year – this one will finish in 2041, by which time I’ll be nearly 80 if I live that long – with a problem effectively solved by Ian Page and his Classical Opera in placing works by contemporaries of various ages alongside young Amadeus’s efforts.

To say this latest revival of the Royal Opera’s Tosca peaks early would be an understatement. The shockwaves rippling out from the brass and timpani in the first few bars set the auditorium rumbling, tumbling the strings into motion. Conductor Emmanuel Villaume seizes his audience and refuses to let go, dragging us in to join the dance of the Sacristan’s sleekly self-satisfied music with its sacrilegious whiff of the Palm Court.

Debussy’s Pelléas et Mélisande is a drama played out in shadow. Shine too bright, too unyielding a directorial light on it, and the delicate dramatic fabric – all unspokens and unspeakables – frays into air. Just over a year ago, director David Edwards and the Philharmonia Orchestra gave us a semi-staging of exquisitely allusive simplicity, leaving the music to fill the gaps between symbol and emotion.