The problem of describing American radio and television lies in the simple fact: there’s so much of it, so many different types and so much variety. At the end of the 20th century there were over 9.000 individual radio stations operating in the United States. By this time their number has grown dramatically. There are public and educational radio stations. They are owned and operated primarily by colleges and universities, by local schools and boards of education, and by various religious groups. At the same…