For the first time an orchestra in mainland China is taking on a foreign music director: the French conductor Michel Plasson is becoming music director of the China National Symphony Orchestra.  

Neville Marriner puts down his cup and saucer and waves an invisible baton around the living room of his Kensington, London, home.  

As Valery Gergiev leads the London Symphony Orchestra in its season opener, the mesmerising, controversial conductor talks to Ed Vulliamy