A giant stage curtain designed and signed by Picasso for the Ballet Russes was displayed for the first time in 20 years yesterday to highlight the treasures the Theatre Museum in London hopes to display if a £12m redevelopment goes ahead.
The stunning backdrop, made for the choreographer Diaghilev's production of Le Train Bleu in 1924, was unrolled on the floor of the Vilar Floral Hall at the Royal Opera House because it is too big to show in the nearby Theatre Museum.
The museum has raised £750,000 so far and intends to apply for £9m in Heritage Lottery Funds for the redevelopment. It wants the work to begin in 2005, when the London Transport Museum, which lies above it, will itself be revamped.
The aim is to double the amount of exhibition space so that the museum can show more of its collection of costumes, scripts and props from decades of theatre, ballet, circus, music hall and puppetry. It even possesses a sizeable collection of rock and pop memorabilia, including items from the Beatles and Rolling Stones.
The actors Simon Callow and Prunella Scales added their support to the scheme yesterday. He said: "The history of the British theatre is as rich as any country in the world's and we have wonderful materials which should be shown and shared.
"The point is really to interest the public, not only in this play or that play but in the whole mix of theatre, the whole activity of putting on plays."
Prunella Scales said the museum's collection was fascinating, but "ludicrously underfunded and not well-housed. This is an occasion to try to raise interest and funding to develop the museum. The country should be proud of it."
Mark Jones, the director of the Victoria and Albert Museum, of which the Theatre Museum is a part, said the Picasso stage curtain was one of the jewels in its unrivalled collection. It was used for several years by the Ballet Russes while it travelled around Europe.
Le Train Bleu brought together Jean Cocteau, who wrote the story, Coco Chanel, who designed the costumes, and Darius Milhaud, who composed the music. The V&A has owned the curtain since the 1960s, but it has languished in storage for two decades for lack of space. Another backdrop by Picasso is on the market for £3m to 4m.
Geoffrey Marsh, the Theatre Museum's director, said the planned exhibition space would allow him to illustrate what human beings were capable of with voice and movement.Reuse content