Bizet's opera Carmen remains one of the most popular in the repertoire, with one of the most intriguing female leads. Laura Cumming explores the many faces of Carmen as a new production transplants her to the 21st century as queen of the cyber chicks. Plus news from the world premiere of The Peony Pavilion, a 22-hour-long piece of Kunju opera about a beautiful woman and her dream lover written by the man described as the Shakespeare of China, Tan Xianzu. It is being performed in New York in its entirety for the first time for modern audiences, who are encouraged to chat, eat and drink tea. Producer Nicki Paxman