A tousled-haired child wearing wings is framed in a candlelit casement window. It’s a beautiful, Georges de La Tour-like scene. He’s the angel of the Lord in a nativity play rehearsal: unto us a son is born, peace on earth. But hark – why is the soundtrack so piercing and Psycho-ish? And why has this little angel (Tom Sweet) left the rehearsal to throw stones at people in the darkness?

American photographer William Eggleston is famous for dedicating himself to colour photography at a time when it was still considered kitsch – acceptable for wedding and Christening photos, but not much else. The best known example of his embrace of colour is a 1973 photo of a red light bulb hanging from a red ceiling, a picture devoid of subject matter beyond redness and the associations it triggers.

Winifred Knights (1899-1947) was an impeccable draughtsman: her portrait drawings are compelling. She deployed fine webs of lines, her sure hand applying gradated pressure resulting in mesmerising studies of people that are hypnotically fascinating. Who knew pencil could do so much? But she was also a painter, a slow worker using techniques that were deliberately old-fashioned.

Nous avons Brexité but we are still welcome at the 47th Rencontres d'Arles. Each summer this beautiful French town gives itself over to an international photography festival which this year features around 40 exhibitions of varying sizes with countless lectures, parties, book signings and fringe events.

And so it ends: Hagen drowns, Valhalla burns, and the ring returns to the Rhine, while somewhere beneath – Wagner’s dawn trumpets sounding faintly in the distance – the dwarf Alberich continues his lonely scheming. It would be hard to find a more apt conclusion to a week of power-grabbing and back-stabbing than Götterdämmerung, and harder still to see its climactic conflagration as anything other than horribly prophetic. But where politics wreak chaos, so art must console, and this Ring cycle is consolation at its absolute purest and most ecstatic.

Boy meets girl; girl and boy fall in love; boy loses girl. In true bohemian fashion, La bohème can lay its operatic head anywhere from Paris to Peshawar, in any era from 90s punk to the Belle Epoque, and still make sense. What matters are the emotions; do we believe in the relationship between Rodolfo and Mimi, the camaraderie between Rodolfo and his friends?

One can only speculate about the mysterious allure which dictators seem to hold for Jonathan Meades, and perhaps one should keep one's conclusions to oneself to avoid reprisals. Having previously turned his perverse eye and tumultuous vocabulary on Stalin (Joe Building) and Hitler (Jerry Building), Meades arrived perforce at Ben Building, in which (with director/cameraman Frank Hanly) he took a trip around Benito Mussolini and the cultural trappings of fascist Italy.

Painted during his first trip to Paris in 1900, Picasso’s Le Moulin de la Galette is an outsider’s view of an exotic and intimidating new world. Men and women are seen as if through some strange distorting lens, their blurred, mask-like faces indistinct but for red-slit mouths and coal-black eyes. We seem to be in the room with them, and yet we are isolated. Even a woman looking out from the edge of the canvas gazes straight past us: if not invisible, we are certainly inconsequential.

Last seen at the National Theatre over 10 years ago, Brecht and Weill’s The Threepenny Opera is back in a new adaptation by Simon Stephens. But looking at Rufus Norris’s epic-theatre-lite production – all exposed stage-mechanics and makeshift sets – and listening to Stephens’s brutal but non-committal text, you’d swear it had never been away. There’s no aggressive update, no attempt to reinvent or make relevant, and the result is a clean, cold stab of a show, a theatrical assault every bit as cool and casual as Mack’s own murders.

The second exhibition staged by Damien Hirst in his stunning Newport Street Gallery is of work from his collection by the American artist, Jeff Koons. Hirst was still a student at Goldsmiths when, in 1987, Charles Saatchi showed Koons and other young Americans at his gallery in St John’s Wood. Hirst was blown away by the freshness and ambition of work that took Warhol’s love affair with consumer culture one stage further. This mini-retrospective can be seen, then, as a tribute both to Saatchi and Koons – inspirational figures in the 1980s.