It's amazing to think that Marcel Proust first heard Wagner's four-and-a-half-hour opera Die Meistersinger down his telephone. That same day, in 1911, he also ingested three hours of Debussy's Pélleas et Mélisande. We learn all this from Edward Seckerson's brilliant new Radio Three documentary about the remarkable world of the Théâtrophone, a device that used telephone transmitters to relay operas - and later news and sermons - live from wherever (the Opéra Comique to begin with) to hotels and houses around Paris. By 1893, this prototype radio had 1,300 subscribers; takers included the King of Portugal and Victor Hugo. The pleasure telephone industry spread first to Hungary, where one of Edison's assistants, Tivadar Puskás, had set up one of the world's most advanced telephone networks, then to Britain and the Americas.