Chinese composer Tan Dun could never be accused of elitism or lack of imagination. The 57-year-old, who is probably China’s most famous classical music export, has a history of accessible yet sophisticated works behind him. His virtuoso Pipa Concerto combines a traditional Chinese instrument with a Western symphony orchestra, his opera The First Emperor was composed for the legendary Plácido Domingo (who Tan now counts as a personal friend), while his film scores for the Martial Arts Trilogy (Crouching Tiger Hidden Dragon, Hero and The Banquet) have brought him recognition well beyond the regular classical music crowd.

His latest work, however, is perhaps his most original yet. Nu Shu: The Secret Songs of Women is written for harp, orchestra and microfilm no less, but even more remarkably, it incorporates a secret language so ancient that its origins are lost in the mists of time. “It was five years ago I first heard this very interesting tradition from my home province of Hunan,” Tan Dun says, speaking to me on the phone from his busy office in China. “It’s a language that has survived only through mothers singing to daughters down through the generations. I was fascinated”.

Nu Shu was whispered in secret exclusively...