This program tells the complete story of radio, from its roots in Marconi’s wireless telegraphy and the invention of the vacuum tube by Lee De Forest, to its heyday in the 1930s and subsequent upstaging by television in a battle for audience-share. Academic experts discuss the impact of early innovators like Frank Conrad of station KDKA, Pittsburgh, who broadcasted from his garage; the power of personalities to influence mass audiences, citing FDR, Edward R. Murrow, and Orson Welles as examples; radio’s role as a vehicle for delivering mass audiences to advertisers; and the superior ability of the radio to entertain and actively engage listeners in the "theater of the mind." This program provides an intriguing look at America’s once-dominant mass medium. (28 minutes)