'We broadcast to the world, about the world' – John Tusa

Special edition from the BBC Radio Show at Earl's Court, London, celebrating the 21st birthday of BBC domestic radio in its current form. Also, reporting on the 50th anniversary of the World Service broadcasting in other languages. "We are Britain's voice to the world. We broadcast in the national interest but we broadcast to the world, about the world," says John Tusa, managing director of World Serivce in ths interview.