I’ve been going to the Wallace Collection off and on for well over half a century and I never tire of its amazing store of treasures. I was little more than a toddler when I first fell for the charms of The Laughing Cavalier, even though it soon dawned on my young mind that Frans Hals’ iconic subject was not really amused. And I quickly developed a deep appreciation of the dark beauty of the Van Dyke portraits and the glorious colours of the Rubenses. Later, I came to adore Poussin’s exquisite and mysterious Dance To The Music Of Time and the gorgeous De Hooch interiors. Now, decades on, I have finally turned my attention to the Wallace’s trove of Dutch still lifes. In particular I love those by Jan Weenix, who evidently believed a memento mori should be full-blooded in every sense and rendered the details with astonishing skill. There are a dozen or so on show and it’s worth a trip to central London just to see them. No matter how often I visit, however, I can’t find anything good to say about the huge Boucher series on the stairs or the chocolate-boxy Fragonards. But they won’t keep me away. Who knows – in another ten years I might even fall in love with them too.

A new occasional musical series at the Queen’s House in Greenwich was launched with a harp recital by these Trinity Laban students. And what a joy it was. Not only was the playing of the young Spaniards magnificent but the setting of Inigo Jones’ Great Hall – now gorgeously adorned with Richard Wright’s gilded artistry – and the space’s incomparable acoustics made this ian unforgettable experience. Garcia played with a swagger, his programme including Scarlatti, Debussy and, best of all, Khachaturian’s Oriental Dance and Toccata. Cotuna, by contrast, held her harp as if she were dancing with it and gave us a more lyrical programme that ended with Fauré’s lovely Impromptu Op86. I look forward to many more recitals in this fabulous building. But a warning to future performers – Garcia and Cotuna have set one heck of a standard.

The National Portrait Gallery has this year pretty much nailed the history of depicting the human form in post-medieval Western Europe thanks to its summer show, The Encounter, featuring paintings and drawings by the likes of Leonardo, Holbein, Dürer and Rembrandt, and the spring exhibition of amazing portraits by the great 20th century British colourist Howard Hodgkin. Now curators have supplied the missing link between traditionalism and modernism with 50+ paintings by Paul Cézanne – about a third of his lifetime output of portraits – which reveal how he moved away from producing recognisable likenesses and opened to door to Picasso’s revolutionary cubist approach. It’s a stunning selection, summed up by three pictures that mark the beginning and end of his career: an extraordinarily sinister red-tinged self-portrait in his early 20s and one showing him in a jaunty beret painted just before his death 40 years later. The latter hangs next to a gorgeous painting of Cézanne’s Provençal gardener who sits bathed in Mediterranean sunshine – in stark contrast to the gloomy browns, blacks and grey that dominates the other works. The pictures in between this triad spotlight subtle but inexorable development of Cézanne’s genius and explain precisely why he is so revered by both public and artists. A fabulous exhibition.

The Royal Academy is the hottest ticket in town at the moment because of the wonderful and huge show of Johns’ work covering the past six decades. The exhibition is a semiotician’s wet dream with its plethora of numbers, flags, maps, targets and letters. But this is not dry intellectual posturing – it’s also stunningly beautiful. Highlights are the 12 bronze rectangles bearing the numerals 0-9 in relief, each markedly different for the others yet laid out in an identical pattern; the discrete triptych Voice2 with its fabulous splashes of primary watercolour; and the stunning Regrets series from 2014. A couple of years ago Johns was part of a sensational Barbican show that linked him, unforgettably, with the composer John Cage, the choreographer Merce Cunningham, the artist Robert Rauschenberg and pioneering post-modernist Marcel Duchamp. The latter’s influence is even clearer in the RA exhibition because in the neighbouring suite of rooms Duchamp’s intensely thoughtful and challenging works share a display with his friend and erotic brother in arms Dali. It’s a fascinating combination which contrasts the breadth of Duchamp’s vision with Dali’s frankly shallow masturbatory fantasies. The Spaniard may have been a fantastic technician but he lacked his French comrade’s soulfulness and intensity and the groundbreaking spirit that – no wonder! – inspired Johns. If you plan to see both shows, look at Duchamp’s stuff first because it sets the scene both historically and artistically. But don’t spend too much time on the Dalis: hurry next door instead and revel in the genius of the real star of the RA’s season.

The French have produced more than their fair share of modernist composers, from early pioneers such as Debussy and Fauré to later 20th century giants including Satie, Poulenc, Ravel, Messiaen and Boulez. So how has Darius Milhaud passed me by? Not only did he write great works but he also tutored some of the musicians who created the soundtrack of our lifetime – jazz pianist Dave Brubeck, songwriter Burt Bacharach and minimalism trailblazers Philip Glass and Steve Reich all studied under him. Fortunately the Hosier Quartet scattered the clouds of my ignorance with a Charlton House recital built around Milhaud’s Sonata for Flute, Oboe, Clarinet and Piano – which happen to be the instruments played by Guildhall School of Music virtuosi Fiona Sweeney, Caitlin Heathcote, Raymond Brien and Emilia de Geer. They brought the piece’s four movements to life despite the challenging time-signatures, multicultural polyrhythms and jazz-tinged syncopations which would have defeated many a fine musician and certainly divided the audience. But all power to them, say I, because the discovery of Milhaud is a joy as well as a welcome extension of my knowledge. And as to its challenges, well, we all need those just to keep the old grey matter churning away under our grey hairs…