When the director Christof Loy’s production of Wagner’s Tristan und Isolde first opened at the Royal Opera House in 2009, some of the audience were in for a shock.

The set was dominated by a long, high, diagonal wall; and people seated on the left-hand edge of the auditorium found their sight lines virtually non-existent. Loud booing resulted on opening night; anybody would be angry after paying Wagnerian prices – in every sense – for an opera they could scarcely see.

Beyond the wall, though, the production was psychologically fascinating; and now it is back to Covent Garden starring, as Isolde, Nina Stemme, widely regarded as today’s greatest Wagnerian soprano. And the angle of that wall has been shunted by a few degrees; the theatre is offering a reduced price on seats where the view is still restricted.

Unlike mainstream theatre, opera is not blessed with a run of previews in which the creative team can fine-tune the staging and catch any likely bloopers. If something goes wrong, it tends to do so under the spotlight of acerbic critics and full-price audiences. Mistakes happen – this was a biggie – but how much can and should a production be changed if it goes over badly with its audience?

Most directors would naturally regard the idea as anathema. A good director has, in certain ways, to function as a benign dictator to realise a consistent concept; and anybody would need the hide of a large reptile to shrug off negative reactions. Mucking around with a show to try to please everyone risks pleasing nobody; besides, controversy is often a driving force in opera. If something strong is being said, somebody, somewhere, is bound to dislike it.

And in the best cases that is exactly why the director should stick to his or her guns. The 1976 production of Wagner’s Ring Cycle at Bayreuth by Patrice Chéreau, set during the Industrial Revolution, was greeted with considerable revulsion at first, yet in due course it became a true classic.

On the other hand, sometimes one gets the feeling that the creative team is so close to a concept that practical problems are not evident until they are tested in public. Take the incident now known, horribly, as “dumpygate”. At Glyndebourne this summer, Richard Jones’s new production of Strauss’s Der Rosenkavalier drew disapprobation from critics for the physique of its Octavian, a young male character sung by a female performer. Maybe Jones wanted to point up some underlying homoerotic forces in the piece by presenting a feminine-looking Octavian – but the result sparked hideously cruel comments. Eventually Octavian was taken out of pale hosiery and jacket and refitted in the more flattering shades of black and plum.

One production that keeps changing, yet apparently to little avail, is the Mariinsky’s staging of Wagner’s Ring Cycle, which has just visited Birmingham. Its concept – basing the opera’s gods, monsters and occasional humans on mythological symbols from Scythian and Ossetian legend with a dash of ancient Egypt – was devised by the conductor Valery Gergiev and designed by George Tsypin; but no consistently present stage director has run the show. When it toured to the Royal Opera House in 2009, its infelicities included dramatically disastrous visible entrances and exits, among plenty more avoidable issues. One critic described the staging as “a disgrace”.

Some reactions from the production’s Birmingham outing suggest that certain aspects may since have been improved – but not enough. “This is one production we certainly don’t need,” said one reviewer. Sometimes no amount of tweaking can fix a fundamental fudge-fest; a fresh start is preferable.

But pulling a production completely is a desperate measure. Last year the director Burkhard Kosminski, tackling Wagner’s Tannhäuser for Düsseldorf’s Deutsche Oper am Rhein, set his production in the Third Reich, exploring, graphically, the theme of individual guilt under the Nazis. Controversy was anticipated – and Kosminski agreed after the dress rehearsal to shorten a scene that depicted Tannhäuser being compelled to shoot a family. But after heckling in the audience and protests from the Jewish community, the intendant made the drastic decision to withdraw the production. The theatre’s statement said that some audience members had been so stressed by it that they required “medical attention”. The shocked Kosminski, in an interview, described the cancellation as “the censorship of art”, adding: “That is the actual scandal.”

Luckily, such ruinous responses are rare. In October the Met in New York pressed on with John Adams’s ever-controversial opera The Death of Klinghoffer (which focuses on the issues surrounding the brutal murder of a Jewish cruise ship passenger by Palestinian terrorists), despite street protests and orchestrated in-house disruption on the first night. The opera house ended up with a triumph. Accusations that the work is anti-Semitic were roundly discredited, review after review declaring the notion nonsensical; and the Met soon announced that the production, by Tom Morris, had sold more seats in the week after its opening than any other opera in its repertoire.

Move a misplaced wall, by all means; make a concept’s points clearly, though perhaps without sending attendees to hospital; but opera directors and intendants should be ready to stand their ground. That’s what they are there for.