The document provides a history of radio from its origins to the present day. It discusses the following key points:
- The birth of commercial radio in the 1920s with the rise of radio networks like NBC and CBS.
- The growth and regulation of radio in the 1930s-1940s including the establishment of the FCC and the development of FM radio.
- Changes in the post-war period from 1945-1990 with television overtaking radio for entertainment and the growth of specialized radio formats and FM.
- Recent consolidation of the radio industry resulting in most stations being owned by a few large companies and new digital technologies changing the radio landscape.