Between the beginning of the 1950s and the end of the 1970s, the American entertainment industry functioned within a durable structure. In this period, what might be called the sound revolution that had begun in the 1920s with radio and talking movies reached its full maturity. Each medium had its specialty. Television supplied situation comedies, dramas, and variety shows to American homes during the evening hours on a daily basis. Radio filled the spaces of daily life that were not easily covered by television, such as the frenetic period in the morning when family members went off to work or school, or the quieter, more private time in the evening when a young teenager did her algebra homework with rock and roll playing in the background. The movies remained the major form of entertainment that people watched outside the home – one went to the movies for a night out or an afternoon’s escape from the tedium of daily life, more of an occasional treat than a regular routine.
In the 1970s, new technology brought new entertainment formats that came into wide use in the 1980s and upset the existing structure. Satellites beamed radio signals down from space. Television, an industry once firmly anchored by the three networks, benefited from new satellite and cable applications that greatly expanded the choices available to viewers. Finally, the movies, the most enduring of all the elements of American entertainment between 1920 and 1970, became available first on videocassette and then on DVD, which made it possible to show almost any film on a home television set. Soon after all of these things happened, the Internet blossomed as an entirely new platform for entertainment.