Let’s get one thing straight at the outset: Szymanowski’s 1926 opera Król Roger isn’t a lovely occasional oddity, a rarity whose appeal is largely novelty, or a dust-it-off-once-a-decade sort of piece. It’s that rarest of things, a real and original masterpiece whose worth has been unaccountably undervalued. This new production by Kasper Holten does nothing to obscure its beauty, making a strong case not only for the work’s sensual appeal, but also the larger philosophical architecture underpinning this maverick score.

A journey into dreams through songs from Dowland to The Kinks; a Swiss director who, Covent Garden’s Director of Opera Kasper Holten assures us, is “one of the most important European theatre artists”; a Norwegian chanteuse who, I assure you, is a performer of real originality. All that should add up to something just a little bit extraordinary, shouldn’t it? Sadly not. What I saw last night was the kind of thing I’d shrug off having chosen at random from offerings at the Edinburgh Fringe.

What kind of regime, asks Gérard, talks of justice while killing poets? It’s a question the answer to which suggests itself all too swiftly this week, briefly turning a revolutionary romp of an opera into something rather more chilling. Playing things straight in his new production of Andrea Chénier (if wigs and lavender stockings, chandeliers and pastoral divertissements can be called straight), David McVicar may have missed a trick with a story that speaks with surprising clarity about the violence of political and ideological conflict. Or maybe he didn’t.

It’s quite a distance from the first performance of Monteverdi’s operatic cornucopia under the Mantuan Gonzagas’ imperious eye to this democratic celebration at the Roundhouse – 408 years, to be precise. Michael Boyd’s production takes us back even further, to those ancient Greek festivals of poetry and music which inspired the intellectual Florentines to fashion the art of opera in the late 16^th century.

When everything works – conducting, singing, production, costumes, sets, lighting, choreography where relevant – then there’s nothing like the art of opera. But how often does that happen? In my experience, very seldom, but not this year. It's been of such a vintage that I couldn’t possibly choose the best out of six fully-staged productions – three of them from our only native director of genius, Richard Jones, who as one of his favourite singers, Susan Bullock, put it to me, deserves every gong going – and one concert performance.

First the good news. At 73, is Plácido Domingo anywhere near retiring? Er, no. When the question came up in an interview on Sunday (on video below), he answered : "The reason I don't retire is because I can still sing." And then with a glint in his eye: "I still feel I have to know the the right moment. Not to sing one day more.... nor one day less."

The best that you can usually expect from an interview is that it takes off from stock beginnings in spontaneous and unexpected directions. This one was rather exciting from the start: the end of a day in the life of a new role, Puccini's good-time girl Manon Lescaut, for lyric-dramatic soprano Kristine Opolais.

Poulenc’s Dialogues des Carmélites is a special and very particular opera. There is nothing else quite like it. Just as the drama - set to the composer’s own libretto - teeters between fear and faith, so too does Poulenc’s score, an extraordinary apposition of austerity and lushness where belief is harmonically consonant, festooned in seraphic harp glissandi and warmly homogeneous middle-voices. But fear is omnipresent in the shadows punctuating the score with a succession of precipitous dissonances and the alien sonorities of instruments like the piano.

The German soprano Diana Damrau has had the role of Violetta Valéry in La Traviata in her sights for a very long time. As she has explained in interviews, seeing the Zeffirelli film of the opera, with Teresa Stratas in the title role, as a 12-year old was a decisive moment in making her want to become a singer. That was 30 years ago.

The Sam Wanamaker Playhouse, the new indoor Jacobean theatre at The Globe, is an absolute jewel of painstaking historical research and craftsmanship. It is small, seating around 350, and with its thrust stage lit by around 100 candles (with electric light only on the musicians’ gallery in this performance), it is a challenging space to put on an opera, but also a uniquely atmospheric one.