Once upon a time, there were two cultures, and they were at odds. A forested wilderness stretches between the kingdoms of Sealand and Lagobel, as we glean from the childishly-drawn, giant map that serves as a front cloth for the NT's new musical spectacular – directed by Marianne Elliot and opening in the Lyttelton last night. The map shows, on one side of the wilderness, Sealand’s coastal realm with winding rivers and a chateau bristling with turrets, all in shades of blue.

In a moment of scalding intensity at the climax of Ghosts, terrified Oswald sees the sun. Throughout the rest of Ibsen’s celebrated drama about the sins of the past, light is fairly absent. Merely cataloguing the disasters that befall its heroine Mrs Alving would certainly indicate a play living up to Ibsen’s bad reputation as the leading dramatist of doom and gloom.

Technology and dance have long been ardent bedfellows. No other theatrical art gobbles up illusions and tricks quite as greedily and spits them out quite as intriguingly altered. Gaslight was a new technology without which the romantic ballets Giselle and La Sylphide could not have existed. Without electric light such exotic adventures in sunshine as Le Corsaire or Don Quixote could not have partied over the late 19th-century St Petersburg stage.

The bells ring out for creativity in the Royal Ballet’s final production under its outgoing director, Monica Mason, and the ambition at least of the enterprise is hugely to be cheered, even if asking seven choreographers to work together is on a hiding to nothing.

Three paintings by Titian depicting stories from Ovid’s poem Metamorphoses welcome you to the National Gallery’s exhibition Metamorphosis: Titian 2012. Diana and Callisto shows Diana casting out the pregnant nymph Callisto from her company. Diana and Actaeon depicts the young Actaeon out hunting and stumbling into a sacred grotto where Diana and her nymphs are bathing; and in The Death of Actaeon, we see the goddess exacting vengeance on the intruder by turning him into a stag to be torn to pieces by his own hounds.

It takes more than utmost craft and rich personality to hold the stage as a soloist - it takes a touch of divine self-belief, which Akram Khan has never displayed to more magnetic effect before than in his new solo DESH. Actually solo is too small a word for this epic, lavish display of the starpower that Khan now emits in the world of dance theatre.

The designer of a fairytale ballet is far, far more important than the choreographer. It's those visions that lodge themselves in children's heads, in adults' memories, embedded with the music. And at no time more potently than Christmas when it's time for The Nutcracker and Cinderella.

Sergei Diaghilev was not short of self-belief. He appointed himself the man to introduce European modern art to Russia and then Russian modern art to Europe as the 20th century began, and in doing so he defined himself as the ultimate artistic director, as the remarkable, tentacular exhibition at the V&A Museum that opened yesterday shows. Reviewed elsewhere on theartsdesk, the exhibition's mounting has thrown up extraordinary inside dramas - the telltale paper found in the boning of a 1916 tutu, the unlikely discovery of a stellar bust in a junk shop, and the legendary artists' sweat that no cleaning can obliterate.

Sergei Diaghilev was not short of self-belief. He appointed himself the man to introduce European modern art to Russia and then Russian modern art to Europe as the 20th century began, and in doing so he defined himself as the ultimate artistic director, as the remarkable, tentacular exhibition at the V&A Museum that opened yesterday shows. Reviewed elsewhere on theartsdesk, the exhibition's mounting has thrown up extraordinary inside dramas - the telltale paper found in the boning of a 1916 tutu, the unlikely discovery of a stellar bust in a junk shop, and the legendary artists' sweat that no cleaning can obliterate.

Theatre designers rarely make a name for themselves. They have to queue up for applause behind the writer, the director and the cast. It’s no surprise that they often seek creative control by working outside the box. Es Devlin has designed shows for Lady Gaga and the Pet Shop Boys. Peter Mumford has created a remarkable light installation on a screen above the altar at Guildford Cathedral. And now Ralph Koltai is unveiling his sculptures.

For the past five years British stage designer Es Devlin has been creating extraordinarily ambitious and imaginative sets for some of the biggest crowd-pullers in the music industry, from Take That to Lady Gaga. But this week she returns to her theatrical roots with a new play, Pieces of Vincent, by David Watson at the small but prestigious Arcola Theatre in London.