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.

If they remember the 1960s at all, the ageing population of Bexhill-on-Sea will remember Bridget Riley for her black and white experiments in perception. The iconic results of this line of enquiry can still result in a “happening” for the eyeballs. And that’s exactly what you get from the earliest paintings in this show: uniform stripes of black and white that won’t for a moment stay still. 

For all the wrong reasons, the work of Dexter Dalwood serves as a useful metaphor for this exhibition. Trite, tokenistic and desperate to look clever, Dalwood’s paintings are as tiresomely inward-looking as the show itself, which is a dismal example of curatorial self-indulgence at the expense of public engagement.

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.

The country is groaning under the weight of commemorations, exhibitions, publications and programmes all marking significant anniversaries of World War One, but the underlying message – lest we forget – remains as potent as ever, perhaps even more so in these tumultuous times.

It’s far too easy to think about the history of art as a series of class acts, with one superlative achievement following another. Exhibitions tend to encourage this view, and the notion of a superstar artist is key to persuading us that the latest blockbuster is unmissable.

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.

The Iranian-born New York resident painter YZ Kami, now in his mid-fifties, continually plays with our hunger to look at “reality” while being seduced by abstraction and repetition. In 17 canvases, painted over the past two years, Kami explores two distinct and recognisable styles or idioms that however much in common they have with contemporary concerns he has made his own. The results are both powerful and pleasurable. 

At 86, Jo Baer is still painting vigorously. In the mid 1960s, she was an established New York Minimalist along with artists like Carl Andre and Sol Lewitt; but while they continued to explore abstraction, she changed tack – dramatically, or so it seemed. In the mid 1970s, she turned toward figuration declaring that the “naivety” of Minimalism (its refusal to engage with events in the real world) no longer made it relevant. Yet she still thinks of herself as an abstract painter and this survey, which spans 55 years, allows us to guage what she means by the claim.

MK Gallery has a knack for showcasing mid-career artists before any other public space and this is Ellen Altfest’s first survey in the UK. There are 22 paintings here which, given their demands on her time, represent a significant proportion of the 44-year old’s output to date. Most of the pieces come from private collections, representing her commercial success with White Cube.