Five of Leoš Janáček's 10 operas are staples of the worldwide repertoire. Two I'd never seen on stage, so the slice I chose of the19-day festival devoted to all of them for the second time in the history of Brno, the cultured Moravian capital where he spent most of his life, tended to the rare and local.

Marx is having a terrible day. He is supposed to be finishing volume two of Capital but he’s distracted by his lust for the maid, workmen are taking away the furniture, his daughter thinks she’s caught a spy.... and what will his wife say when she discovers he’s taken her silver to the pawnbroker?  Where is Engels when Marx needs him most?

Mid Wales Opera makes small-scale touring look fun – even when you suspect that, behind the scenes, it really isn’t. Barely 24 hours before this performance of their current production of Ravel’s L’heure espagnole, and 11 dates into their current 16 date tour, their Torquemada, Peter van Hulle, was invalided out. Companies this size, and working on this budget, can’t carry understudies.

Before we hear a note, extras dressed as maintenance staff potter about the stage. They try to erase a scrawled slogan on a wall that reads “Hur allt började”: how it all began. “It” is the story of Wagner’s Ring cycle as presaged in the introductory drama of Das Rheingold, which kicks off the tetralogy. Prior, though, to the ominous, mesmeric swell of the E flat chord that anchors the Rheingold prelude, Stephen Langridge’s production for Gothenburg Opera shows us a busy, dogged human world of toil.

We’re not good at lack these days. Just look at the concert hall, where increasingly you turn up to find not just an orchestra and soloists but a giant screen. Videos, projections, live speakers, "virtual choirs"; if there’s so much as a chink of an opening in the music, you can bet that someone will try and fill it. It seems to come from a place of generosity, a desire to reach out, to supplement, to amplify, to explain, just in case we didn’t feel or see or understand before. But it’s also a gesture that takes away our agency as an audience, turns us spongy, limp as listeners.

Political machinations and backroom power-brokering, leadership battles and unscrupulous rivals – if ever there was an opera for this week it’s Simon Boccanegra. Premiered in 1857 but only coming into its own after substantial revisions in 1881, Verdi’s problem-child of a piece had its own struggle for survival and success, and the work’s rather lumpy dramatic architecture shows the scars of its various grafts and interventions.

In a week of flickering memorial candles and cascading poppies we’ve all been asked to contemplate the pity of war – to remember and to seek consolation in beauty and silence. But before we can earn that consolation and mourn in that silence there must surely be rage and noise, bloody specificity before aesthetic abstraction.

Lightness and gravity in perfect equilibrium have always graced Vladimir Jurowski's Stravinsky.

What a scrumptious spread of musical virtuosity the Barbican has laid on with the aid of its international guests this week.

Presenting the last Mozart symphonies as a three-act opera for orchestra, as Richard Tognetti and his febrile fellow Australians did on Monday, was always going to be a supreme challenge. It worked, as Boyd Tonkin reported here. Since then, the Barbican's grandiosely-named "International Associate Ensemble" has opened up the repertoire, synchronising with film (on Tuesday) and ending its mini-residency with the kind of vibrant rattlebag for which it's rightly celebrated.