One of the baleful byproducts of the last three years has been the engagé opera production. Sure, it happened before — a rash of Guantanamo-chic orange jumpsuits broke out a few years back — but lately the oddest pieces have turned out (fancy that!) to be actually all about Brexit.

In 2020, if you’re still hankering for something political, my advice is: don’t be looking at Fidelio. In Beethoven’s 250th anniversary his sole opera will be inescapable (not that you’ll be able to get a seat at Covent Garden in March: they were snaffled by the most gilded stratum of Friends within five minutes), but, notwithstanding its thunderous encomia to freedom, the human spirit and staunch, dauntless wives (Beethoven never married), its liberation politics are strictly school-leaver — and hardly the point.

You probably think anyway that addressing politics in opera is about as sensible as tackling astrophysics in mime. But opera has lofty socio-ethical ambitions, upholding its role as Greek drama redux to tone up the audience’s moral and political muscles. Admittedly, this excellent aim has been rather obscured through the ages by various distractions: the lengthy warbling of Italian vowels, the audience’s preference for eyeing up the dancing-girls (and boys) or generally carousing, over actually paying attention, as well as opera’s standard model of aristos in big old clothes bombing out with infectious diseases and/or sexual exhaustion — hardly the obvious text for a primer on the virtuous civic life.

The closest it gets to West Wing realism is the bit in Monteverdi’s Coronation of Poppea — the I, Claudius of opera — where Nero and Lucan whoop it up with booze and dirty songs after the emperor has had Seneca top himself: just as Putin and pals partied like it was 65 AD to celebrate the end of Boris Berezovsky.

Now it’s all callow addenda, my top moment to date is the way a neophyte director turned Henry Purcell’s blameless harvest drinking-song in King Arthur (which basically celebrates the joys of scamming the parson of his tithe) into a snarling skinhead anthem, propelled of course by its nauseating refrain, “Hey for the honour of old England!” But opera really doesn’t need the help of activist directors: it’s all there already.

As usual, happily, every opera company in the country is performing Mozart’s Marriage of Figaro this year

In Mussorgsky’s Boris Godunov a crabbed old monk bangs out fake chronicles to gaslight the Tsar (it works: Boris goes mad and dies). In his later Khovanshschina, Mussorgsky has about eight different parties squabbling over Russia’s destiny: a zugzwang of liberalism, reaction and revolution. Mussorgsky’s work may describe obscure seventeenth-century events, but it intimately concerns the fractious state of 1870s Russia, asking good questions about history: who writes it, who owns it, what’s it for? – the basis of a brilliant, pointed production by Birmingham Opera Company not long ago.

It’s not just your turbulent Russians, either: apparently Italian unification was accomplished entirely through the medium of opera. Interestingly, the old Labour leader Michael Foot — a Byron adept, but equally up on his operatic doppelganger Rossini — reckoned the latter’s light-footed Italian Girl in Algiers had more to say, and more powerfully, about yearnings for enosis than all of Verdi’s heavy-duty slaves’ choruses and the like.

And actually opera did make the Austrian plod in northern Italy entertainingly jumpy: in 1837 the ladies’ chorus in a Parma production of that well-known provocation Lucia di Lammermoor was arrested en masse for wearing “subversive” ribbons, and in 1847 the conductor of Verdi’s Nabucco got his collar felt for “conducting in a rebellious manner”.

The outcome of December’s election means we can look forward to another lustrum of lyric militancy. Oddly, you won’t find much politics in John Adams’s Nixon in China, performed at Scottish Opera later this month (if it doesn’t get cancelled when someone hears Mao is being sung by a white guy). Impeccably liberal-minded, natch, it confers a sort of poetic heroism on Mao and Tricky Dicky while reserving its satire for Henry Kissinger, who winds up in drag, taking part in nice Madame Mao’s agit-ballet The Red Detachment of Women.

As usual, happily, every opera company in the country is performing Mozart’s Marriage of Figaro this year (starting with Opera North, Welsh National and Mid-Wales Opera this month), based on a play Napoleon called “the revolution in action”. Foolishly, of course — it’s really a standard French sex-comedy with a bit of ’tude botched in by Beaumarchais to curry favour with Danton and the lads.

Mozart’s aims are different, and far above politics: he uses this story of how the lady’s maid Susanna teaches her betters some lessons about integrity and human dignity to enable a visitation of divine love and forgiveness which will renew the face of the earth — a more ambitious manifesto, and rather more credible, than Jeremy Corbyn’s.

For the rest, expect the simpler joys of the usual betrayals, adulteries, broken promises, deals with the devil, and superannuated girlfriends being bumped off — that have (obviously!) no relation whatsoever with politics.