Not a good start. The tenor (Brian Jagde) walks downstage and sings loudly, if securely, to the audience: hardly a characterisation of an idealistic young Infante meditating on love. The next voice, the Page’s, is barely heard (Ella Taylor gets better). Then we have The Presence: Lise Davidsen, who you know is Elisabeth de Valois in the only carefree mode she’s to experience throughout the opera.

The trouble with Trovatore, Verdi’s sometimes barrel-organish, slightly middle-aged troubadour, isn’t so much the silly shocker of a plot, triggered by a gypsy so crazed with vengeance that she throws her own baby on a bonfire by mistake, as the choppy dramatic line, so hard to thread. Under the circumstance, Adele Thomas’s medieval-hell production could have been a lot worse, and the vocal quality is there throughout under Antonio Pappano’s watchful guidance.

Benoit Jacquot’s handsome period production of Werther has been quietly putting in the miles for the Royal Opera. Since its premiere in 2004, this unexceptionable staging – “this wall, this fountain, this cool shade” all present and laboriously correct – has supplied a London star vehicle for everyone from Joyce DiDonato and Isabel Leonard to Juan Diego Florez, Rollando Villazon and Vittorio Grigolo. Now it’s the turn of Jonas Kaufmann – or, at least, it was supposed to be.

If you’re going to be locked in an auditorium with a crazed soldier for over 90 minutes, you need to be overwhelmed by the human frailty and baseness in Büchner’s still-shocking stage play of the late 1830s, the spiderweb beauty of Berg’s 1925 score to match it and a vision in various stage pictures. Director Deborah Warner, conductor Antonio Pappano and set designer Hyemi Shin deliver on all fronts.

Invasion by a colonising power has convulsed a country, dividing families – even individuals – between the rival claims of resistance and collaboration. A captured freedom-fighter from the indigenous elite faces execution; an imperial general hopes to wed his widow and bring a kind of peace to the conquered land.

To create a sensitive and original music-drama around the subject of a school killing is a colossal achievement. Director Simon Stone, set designer Chloe Lamford and novelist Sofi Oksanen’s cutting libretto make Innocence seem like a masterpiece. I wish I were less ambivalent about Kaija Saariaho’s score.

Nearly 40 years old, Andrei Serban’s Royal Opera Turandot feels like a gilded relic (I felt like a relic myself on learning that my writer neighbour wasn’t born when I saw Gwyneth Jones as the ice princess in 1984). Yet so too, outwardly, did Puccini’s only really grand opera when it premiered in the 1920s, exoticism being mostly confined to operettas and musicals. What keeps it modern is the score, which made it vital to hear what Antonio Pappano had to say with it.

Psychological depths in the myth of the water nymph who yearns for the human world, with disastrous results, have led to some unusual settings for Dvořák’s operatic masterpiece on the theme: a nursery, a hotel room (both successful), a brothel (not so much). What, though, when a production returns to the fairy-tale, developing at the same time the ecological devastation implied in the opera?

It’s always a disappointment when the Venusberg orgy Wagner added in 1861 to his original, 1845 Tannhäuser to suit Parisian tastes gives way to foursquare operatic conventions. Especially so in this revival of Tim Albery’s 2010 production, where Jasmin Vardimon’s choreography (pictured below) seems executed with more brilliance than ever and post-viral vocal problems loomed large last night for this hero.

This multimedia horror revue gave me heart trouble, which is an odd kind of compliment. Not at first: the assault of abrasive music, the one singer having to leap all over the place vocally, competing with spoken word and information overload, can seem self-defeating. And that vile word “lobotomy” is enough in itself to trigger a panic attack. But ultimately the impact is powerful, unforgettable, in tune with great artistic statements about the human condition.