Shot in 2004 when photographer Robert Frank was 80 (main picture), this award-winning film was aired on The South Bank Show the following year, but is only now on release. I hope the experience was cathartic for Frank, because to the viewer it feels as if he is being put through the ringer.

What a superb location for a performance! The flats on the north-east corner of Islington Green back onto a crummy atrium from which a staircase leads down to a vaulted, concrete pit (pictured below). A cross between a car park and a bull ring, or a subterranean version of a de Chirico painting, this huge chamber reminded me of the stark designs of the Italian modernist, Aldo Rossi.

Art historians can so easily get carried away looking for a thesis, a scaffolding on which to hang theories which can sometimes obscure as much as reveal. Not so here: as near perfect as might be imagined, this is a beautifully laid out, fresh look at a master painter, that lights up the National Gallery's basement exhibition space.

Fifteen years ago on a cold grey Saturday in mid-February, Trafalgar Square was filled with people marching to Hyde Park in opposition to the proposed invasion of Iraq. A million people gathered in London. Three times that number turned out in Rome. That day, across Europe and the rest of the world, between six to eleven million people participated in the largest coordinated anti-war rally in history.

Hie thee to Oxford, for it is doubtful that we will see the like of this exhibition again this side of the Atlantic. American art of the 1920s and 1930s was once disregarded in its homeland in favour of Francophile superiority, and once it fell into critical and commercial favour it became too expensive to move around at the beckoning of would-be international hosts.

Painted in ice-cream shades punctuated with vivid red, the series of portraits made by Picasso in the early weeks of 1932 are as dreamy as love letters. His mistress Marie-Thérèse Walther – we assume it is she – lies adrift in post-coital languor, her body spread before us as a delicious and endlessly fascinating confection.

The American artist, Joan Jonas is one of the pioneers of performance art. Now 82, she is being honoured with a Tate Modern retrospective and Ten Days Six Nights, a festival of live art in which many of her performances are being recreated.

Sometimes you come across an artwork that changes the way you see the world. Tacita Dean’s film portrait of the American choreographer Merce Cunningham (main picture) is one such encounter.

It is a very human crowd at Victorian Giants: The Birth of Art Photography. There are the slightly melancholic portraits of authoritative and bearded male Victorian eminences, among them Darwin, Tennyson, Carlyle and Sir John Herschel.

Mortality inflects commemoration. So it is with portraiture: the likeness – particularly those which celebrate lives of status and accomplishment – will always be limned with death.