The celebrated conductors Pierre Boulez and Daniel Barenboim talk about their friendship and share their views on the art of conducting. Boulez directs the London Symphony Chorus and the BBC Symphony Chorus and Orchestra's performance of Janacek's Sinfonietta, while Barenboim and his West-Eastern Divan Orchestra, formed of young Israeli and Palestinian musicians, perform Brahms's Symphony No 4 in E. Presented by Clive Anderson and Suzy Klein.