It’s been 17 years since apartheid came to an end in South Africa, and the transition to democracy has not been an easy one, for while political systems may change, social attitudes may prove yet more difficult to shift. The Victoria and Albert Museum brings together 17 South African photographers whose work responds to the cultural and social changes their country has undergone. This major survey looks at photography from the last decade: exploring issues of identity across race, gender, class and politics, it provides a vivid snapshot of what it means to be a South African today.

There have been exhibitions, indeed even a whole museum, dedicated to cleanliness: the Deutsches Hygiene Museum in Dresden, for instance (image 9), which was founded for the purpose of public education in hygiene and health, but which later embraced and diffused racist theories during the Nazi era. Yet there haven’t been many – or any, as far as I’m aware – devoted entirely to dirt. It’s all around us, yet historically we seem to have considered the subject unworthy of serious cultural examination. And the reasons for avoidance are just as interesting as the filthy matter currently under the microscope at the Wellcome Collection (see theartsdesk's review).

“I’ve never been intimidated by them. I don't suffer from thinking, that person is a star. They’ve got their job. I’ve got mine. If they’re pleasant so much the better.” Angela Allen’s lifetime in film has found her working closely with some of the most iconic figures in 20th-century entertainment, from matinee idols to gnarled silverscreen pros. Of the 75 pictures on which she was script supervisor, this selection of photographs from her personal album gives some sense of her long and distinguished contribution to cinema, including the occasional bit of body double work when no other appropriate female was around.

Charlotte MacMillan took photographs of the first new full-length ballet at The Royal Ballet for 16 years, Christopher Wheeldon's Alice's Adventures in Wonderland, which premiered last night at the Royal Opera House. Designs are by Bob Crowley, lighting by Natasha Katz, projection design by Jon Driscoll and Gemma Carrington. Music by Joby Talbot, scenario by Nicholas Wright. See theartsdesk's review of last night's world premiere.

From a guitar by Matteo Sellas dating back to Germany before 1630 to one made in New York by John Monteleone in 2008, the Metropolitan Museum of Art’s Guitar Heroes exhibition is will go down as the longest guitar solo slot in history. Including one of the four surviving models by Stradivari, it monitors the guitar’s development in Italy and the instrument’s migration across the Atlantic. Angelo Mannello, born in Italy, made the mandolins seen here in America. It is clear from this gallery, which includes a bespoke instrument made for Paul Simon, that the skill exhibited by the great guitarists is no less an attribute of the craftsmen who design and build the instruments they play.

"There's a similarity between being a soldier and a photographer. They are both looking intensely for the moment." Bran Symondson would know. He served with the British Army in Afghanistan before returning to document the world of the Afghan National Police. A less sensitive photographer might have alighted on the parallel between the action of a rifle barrel and a camera lens. But Symondson's pictures visit a perilous environment where, like that tiny butterfly in All Quiet on the Western Front, a fragile beauty survives and even prospers.

Rudy and Margot do intensely serious barre in an Italian garden, Lynn Seymour enjoys a "Loyal Ballet" poster on a 1962 Japanese tour, in Glasgow two ballet girls snatch some rest in uncomfortable chairs. The real world of ballet, as shot by the insider who became a world photographer, Colin Jones. Read the interview with him, describing the friendships and tragic dramas behind the exhibition of 50 years of his ballet pictures at Proud Chelsea Gallery - events as turbulent as anything onstage.

A display of rarely seen photographs of key ballet dancers from the start of the 20th century goes on display at the National Portrait Gallery. The gallery holds the largest surviving archive of the once-fashionable Bassano Studio, London, including portraits of Anna Pavlova and the great classical dancers Adeline Genée (6), Phyllis Bedells (main) and Ninette de Valois (2), founder of the Royal Ballet.

The unseen Dalí? Surely not. Anyone who ever popped into Dalí Universe, the now defunct gallery on the South Bank which was devoted to the flamboyant Surrealist's work, might well ask. Since there have been so many editions of his well-known sculptures, cast in prodigious numbers both during his lifetime and after his death in 1989, it seems only right and proper to raise a sceptical eyebrow: what more, indeed, is there to discover? And not just this. There’s a further thorny question of authenticity. The posthumous sculptures still manage to fetch a price, of course, because Dalí gave permission for them to be made – so all legal - but purists remain unconvinced.