From its title, you could be misled into dismissing this show as narrow and self-referential: a small exhibition in a small gallery curated by a Belgian artist concerned only with his own countrymen. In fact, it is something of a survey, featuring works with influences that range from Piet Mondrian, Ad Reinhardt and Lucio Fontana, to the Color Field painters.

Light. Light banishes the shadows where monsters lurk and where ghosts rattle their chains. “Give me some light, away!” cries the usurping king in Hamlet as his murderous deed is exposed by the trickery of art. What guilt plagues and seizes his conscience, and yet Claudius, conflicted, cannot pray. He must, therefore, remain a captive among the ghosts and the monsters where no light may fall.

It's impossible to overstate the reverence accorded the painter Agnes Martin by her fellow artists; in the panoply of American cultural goddesses, she is right up there with Emily Dickinson. Yet she is scarcely known in the wider world, partly because her work is relentlessly abstract, but also because she was deliberately evasive.

Time was when a Boulez concert with the LSO would have been directed by the man himself, but that is no longer possible. In Peter Eötvös they have the next best thing, a conductor who has known the man and his music for decades, whose listening ear is scarcely less acute and whose most recent appearance wth the LSO, in Lachenmann and Brahms with Maurizio Pollini, made quite miraculous music from intensive rehearsal.

In 1967 when she produced Syncopated Rhythm (main picture), Sonia Delaunay was 82; far from any decline in energy or ambition, the abstract painting shows her in a relaxed and playful mood. Known as The Black Snake for the sinuous black and white curves dominating the left hand side, this huge, two and a half metre wide canvas is deliciously varied.

Made an Honorary Royal Academician just a few months before he died, in 1993, it’s taken till now for a posthumous Royal Academy survey to finally bring one of the absolute greats of American postwar painting to a UK audience. Of course, for those with long memories, there was the Whitechapel Gallery exhibition of 1991, but though it provided the impetus for the belated honour, it seemed to do little to bring the paintings of Richard Diebenkorn into the public realm.

So, Picasso’s last words turned out not to be, “Drink to me. Drink to my health. You know I can’t drink anymore” – yes, those famous last words that inspired a Paul McCartney dirge – but were, according to this TV biography looking at Picasso’s women and how each significant relationship informed the direction of his work, “Get me some pencils”. A more prosaic request, certainly, but he died in bed, aged 93, his pencils delivered and drawing to the last. It was a good and fitting end.

Russia’s national gallery, the Tretyakov, bears the name of its founder Pavel Tretyakov, the 19th-century merchant who bequeathed his huge collection of Russian art to the city of Moscow in 1892. His bust stands proudly overseeing the entrance to the gallery’s old building, a fine, purpose-built example of early Russian 20th-century architecture.

If what you wanted to do was go out to the middle of the Mexican desert, invert the Cross and dip it in blood, screaming obscenities all the while, surrounded by a sunburnt band of fellow travellers all off their heads on mescalin, Tutuguri is definitely the music you’d want to do it to.

Ernst Krenek is probably best remembered nowadays as the composer of Jonny Spielt Auf – the quintessential Zeitoper of Weimar Germany and later the archetype of all that was designated “degenerate” in art by the Nazi regime. And perhaps also as – briefly – the husband of Anna Mahler, daughter of Gustav. But Krenek was far more than that. He was a magpie collector of styles and influences whose large corpus of work reflects almost every major 20^th-century trend.