When art forms collide, the results can be ambiguous - plays on film are usually stagy, but films inspired by music can be epic. Perhaps the oddest combination is dance and visual art: how do you attempt to represent an art derived from movement in one that is immobile?
This has been a challenge artists have taken up over the centuries, and the latest to do so is Nasser Azam, who last week unveiled his sculpture The Dance outside County Hall on London's South Bank. The Picasso-inspired piece by Azam, County Hall Gallery's artist-in-residence, will be a permanent fixture, next to Dali's Space Elephant.
Perhaps the most prominent image of dance in art at the moment is the Royal Academy's poster of Matisse's The Dance, visible around London. Where Matisse is so successful in representing the motion is in his use of curving lines: the figure on the left is created by a curve stretching smoothly from ankle to armpit, giving the twist that suggests sinews straining. The varying positions of the dancers' legs imply that we have caught them mid-movement.
The most famous artist to depict dancers has to be Edgar Degas, who captured them in painting and sculpture. Sculpture is perhaps more immediately successful, since it is easier to conceive the object as a person frozen in movement, plus all aspects of the moving body can be represented. Having said that, only someone with Degas' skills could really make a permanent object feel like an energetic split second.
Painting is a little trickier, then, since you can only have one angle - at least until Picasso. Here Degas is equally interested in the technicalities of the dance - foot positions, the barre, the stage - as well as the calm or flurried atmosphere of the room. The paintings feel very different from the precise, lively sculptures, and if I wanted an evocation of what it feels like to dance, I would look to the sculptures.
Picasso's 1925 The Dance relies in many ways upon the same things as Matisse's does - the arch of the back rising up to the arm, the legs in motion, the vibrant colours - but he adds extra energy by presenting the dancers from several angles at once, as cubism allowed. These angles - and the shapes, colours and patterns - pull the eye everywhere at once, which in itself creates a sense of movement.These masters - Picasso, Degas, Matisse - presented themselves with a challenge, that of giving the stationary mobility. It throws up all sorts of conceptual and practical difficulties, but as they show, there is no reason why dance and art cannot mix. When they do so successfully, it is a miracle of motion.