Sotto Voce is a collection of white paintings, sculptures and reliefs made by European, British and North and South American artists from the 1930s to 1970s. An accompanying book explains why this non-colour has appealed to so many artists in so many countries over such a long period of time.

The title has it about right: no matter what it is they are busily acquiring, collectors seem to be an obsessive bunch, and their obsessions can achieve quite magnificent proportions. The stereotyped image of the collector as a socially challenged monomaniac doesn’t really fit with the popular understanding of the artistic temperament, though.

A Bloodhound Mark 2 surface-to-air missile points to the sky from the terrace outside the Hayward Gallery. From 1963–1990, the missiles were stationed along the east coast, from Humberside to the Thames, to intercept Soviet planes coming to drop atom bombs on Britain.

It's a chilling reminder of the Cold War and the nagging undertow of fear it engendered; it is also a timely reminder that, in recent weeks, Russian fighter jets have been intruding on our air space to give us the jitters and ratchet up tensions.

Oh, Dr Pozzi! This gorgeous man is garbed in a red wool, full-length robe, almost completely obscuring his elegantly gleaming white shirt. The shirt collar frames his face, casting light, and its frilled cuffs emphasise his improbably long-fingered hands in a lively gesture.

If you bought a Beatles album in the Sixties, chances are you also bought The Mersey Sound, that best-selling collection of poems by the Liverpool poets Brian Patten, Roger McGough and Adrian Henri. It was launched at the Cavern Club in 1967 to musical accompaniment. Their poems felt new, accessible and exciting. "Love is feeling cold in the back of vans," wrote Henri, "Love is a fanclub with only two fans / Love is walking holding paintstained hands / Love is /."

Christian Marclay is best known as the author of Video Quartet, 2002 the most exciting artist’s video ever made. The four-screen extravaganza juxtaposes more than 700 clips from Hollywood movies of people singing, dancing and playing instruments not to mention screaming, whistling or smashing crockery. Formally tight, it starts with an orchestra tuning up and, after a glorious crescendo of brass bands, Scottish pipers and Hendrix guitar riffs, ends with a door slamming shut followed by blissful silence.

"My fatherland is South Africa, my mother tongue is Afrikaans, my surname is French, I don’t speak French. My mother always wanted me to go to Paris. She thought art was French because of Picasso. I thought art was American because of Artforum... I live in Amsterdam and have a Dutch passport. Sometimes I think I’m not a real artist because I’m too half-hearted and I never quite know where I am." (Marlene Dumas)

What does it mean to be a great artist? Is it enough for your work to be admired, studied, emulated and quoted by contemporaries and subsequent generations, or is the value of art judged by a more complex set of criteria? By considering the extent of Rubens’ influence on artists from Rembrandt to Klimt, the Royal Academy is having a go at skinning a very old and troublesome cat: the elevation of Rubens from gifted confectioner to worthy Old Master.

Artangel continues to instigate extraordinary events in extraordinary places. Over the past two decades and more, directors Michael Morris and James Lingwood have helped generate major and ground-breaking work by Rachel Whiteread, Brian Eno, Laurie Anderson, Roni Horn, Jeremy Deller, Steve McQueen, Matthew Barney, Gregor Schneider, Francis Alÿs and many others. It's a long list. Their latest collaboration with PJ Harvey is no less thought-provoking and inspiring than the best of their unique collection of imaginative and risk-taking projects. 

From an apparently simple idea stems a very confusing exhibition. Here’s the idea: taking the seminal black square painted by Russian artist Kazimir Malevich as its starting point – in fact, a rectangle, with the small and undated Black Quadrilateral the first of three Malevich paintings – we are invited, over the span of a century and across a number of continents, to explore the evolution of geometric abstraction and its relation to “ideas of utopia”.