Latest in a series (oil, lumber, etc.), this lively history tells of radio's inception in the early 20's, progresses to its expansion and buildup in the two dominant networks, NBC and CBS. There are close-ups of inside studios, types of programs, issues of free speech and censorship, local stations, reporting. There's a picture of radio in foreign countries, careers offered in this field. As an introduction to an industry, this is informative for those seeking vocational details.