If I asked for your top ten revolutionary artforms, what would you dredge up for me? Vladimir Mayakovsky’s smash-down-the-walls performance poetry? That topless hottie leading the charge in Paris? Diego Rivera? Pretty soon you’d be scraping around with Alexei Sayle’s Marxist-Leninist rock-motown combo, maybe some anarcho-syndicalist macramé and Cuban folk tatting, before shamefacedly offering me bad-faith wretches like The Clash and Neil Kinnock’s Red Wedge of unhappy memory, denounced even by The Housemartins as bourgeois deviationists.

Opera (I’m guessing) wouldn’t feature high on your list, and it’s true the audience don’t look a lot like Red Guards. And yet to listen to those who carry out opera around Europe, its managers and directors, you’d think it was a local offshoot of the Shining Path, the opera house a smoky conspirators’ lair, subversion and revolt plotted amid the heavily subsidised plush and gilt.

Yes, opera is not merely a peculiarly inefficient way of telling a story: your Wagner, Verdi, Rossini and pals are actually engaged in a searing denunciation of Western polity, and though the chaps who run the show here are mostly from Eton and so on they cede to none in Spartist determination to bring the whole shabby charade crashing down by means of radical stagings of The Barber of Seville, or die in the attempt.

To listen to its managers in Europe you’d think opera was a local offshoot of the shining path

Let’s hope it stays fine for them. As it happens, for hundreds of years opera would seem to have frightened the bejesus out of the various regimes that ran Europe so poorly, and battalions of censors were kept busy making sure the public didn’t rush hollering out, throwing up barricades and chucking petrol bombs at the pigs. But need they really have bothered?

There is a report that in 1830 some, inflamed by righteous national feelings, joined a demo outside the Brussels opera after Daniel Auber’s Muette de Portici, and “hence” Belgium was born. More probably they were simply drunk and got lost on the way home. Other than that, we seek in vain for any riotous or even spirited behaviour beyond the routine trashing of the Crush Bar and highjinks in the Gents.

Operamanes, those hair-trigger seditionists, were simultaneously renowned for their delicate sensibilities. So not only did any careless mention of “freedom”, etc, have to be bleeped: numerous iterations of “the stake”, for example, were taken out of Verdi’s Il trovatore, even though this item of correction enjoys a starring role in the opera, and La traviata, premiered in 1853 and based on Alexandre Dumas’s Dame aux camélias of five years earlier, was required to be performed in Louis XIV get-up and set around 1700 in case anyone thought there might be such a thing as prostitution in contemporary Paris.

Of course censorship had its fun side, as when the Germans laughingly threatened to bomb the Copenhagen opera house in 1943 if they didn’t stop performing that Jewish-Negro trash Porgy and Bess. Verdi’s Masked Ball was forcibly removed from eighteenth-century Stockholm to Boston, Mass, and Bellini’s I Puritani had all mention of Protestants removed, which helped the plot no end.

Well, ha ha, indeed, and isn’t the past quaint and funny? But let’s not get too uproarious: plus ça change, plus c’est unimaginably worse — the very worst being that our censorship now is wholly self-imposed, whether out of quaking fear of absolutely anybody’s displeasure, spiritual debility, excessive politeness or sheer bloody wowserdom.

Viz the Australian production of Carmen that was pulled because the heroine likes a fag, or the American high-school pupils who were barred from seeing Donizetti’s jape Rita because it “provides a poor model of marriage and portrays sexism and the acceptance of violence as a means of problem-solving”.

Which takes us neatly to the dreary old Middle East, and the regular cancellation of any performance of John Adams’s Death of Klinghoffer, which outrages “fans of Israel” because Palestinians get to say their bit; continuing via the Berlin Opera pulling Mozart’s Idomeneo when this opera about getting over childish superstitions featured the severed heads of Poseidon, Jesus, Buddha and you-know-who.

There is an antidote to all this moral cowardice and it is called Candide. Leonard Bernstein’s glorious, somewhat rackety Voltaire opera/musical, written in 1956 and endlessly revised, is a love-letter to European music (as West Side Story was to American), heaping contempt on self-righteous prigs, phony moralism, facile philosophies, cant, and all the rest. What better text for a country and continent consumed by sanctimonious hysteria, where competitive censure, whipped up and pandered to by a craven media, gleefully closes down freedom of thought in the very places Voltaire and Co. made it happen? Candide — check out YouTube etc, for available audio/video versions — reminds us the battle isn’t ever done. See you on the barricades, comrades.