Untouched by World War II, American radio stations rapidly expanded in number to more than 2,000 AM outlets by the early 1950s. Most were in smaller markets gaining local radio service for the first time. Beginning with the 1948–49 season, however, network television in the East and Midwest (with national service by 1951) doomed American radio networks. Because American commercial television expanded faster than many expected, radio listeners of 1945 would find a dramatically different system and programs within a decade. The number of network radio affiliates declined by slightly more than half, and network drama and variety programs (which had shifted to television or left the air) were replaced by music-driven local programming. Public-service-oriented radio systems changed more gradually, their mission continuing into television; because of its high cost, however, public-service television grew slowly, thus extending the importance of educational radio.

The rise of rock and roll music in the 1950s greatly aided radio’s sometimes difficult transition. The early and mid-’50s saw the development of “Top 40” programming dependent on hit music and the personality of the local disc jockey, or deejay. Station owners Todd Storz in Omaha, Nebraska, and Gordon McLendon in Dallas, Texas, created the format (tightly timed records with brief reports on news, weather, and sports, plus occasional features and constant time checks and station promotion) used first by about 20 stations in 1955 and by hundreds five years later. Top 40 appealed primarily to teenagers and featured mostly rock and roll music. Elvis Presley’s arrival in 1956 as the first rock superstar helped cement the new radio trend. The radio “payola” scandal of the late 1950s (in which deejays and others took bribes to tout certain records) saw many lose their jobs; the practice went underground, to reappear several times in subsequent years.

Top 40 radio also ended the era of distinct radio “programs,” as the medium now operated in “formats”—broadcasting a certain type of content (nearly always music) all or most of the time. Rather than programs, stations offered different disc jockeys by segments of the day (known as “dayparts” in the business), but the music they played remained largely the same. A few became well known, with each town having one or more who were important to their local audiences. Dick Clark, though primarily a television figure on American Bandstand, epitomized what many deejays tried to do: look clean-cut (and thus less threatening to parents and other authority figures) yet remain highly successful with young listeners and with the recording industry.

Two disc jockeys were representative of the changes in the 1950s and ’60s. Alan Freed, originally an announcer of classical music, became a pop music deejay in Cleveland in the early 1950s and was known to his listeners as “Moon Dog.” His audiences at first were largely black until white teenagers began to hear and like what he dubbed “rock and roll” music. He moved to New York City in 1954 and soon enjoyed huge audiences both on the air and at live concerts. His program was one of the first to be syndicated to several other cities. By 1956 he was the best known of the deejays whose programs commanded two-thirds of the nation’s radio airtime. Yet just two years later he was fired from his New York station because of growing unrest (and the resulting unsavory publicity) at concerts he emceed. Implication in the growing payola scandal was the final straw, and his career was over. He died a few years later at age 43.

By the 1960s Chicago-based Dick (“the Screamer”) Biondi ruled the Midwestern airwaves from station WLS. His raucous on-air personality continually led to trouble with station management. Before he became a “golden oldies” host years later, playing much the same music for the same (now older) listeners, Biondi figured he had been fired from 22 stations in different markets. As with many other radio personalities, he had bounced from station to station across the country before hitting the big time at WLS. And like many in the 1960s, he was constantly doing stunts and concerts both on and off the air to attract and build audiences (and advertising revenue).

Radio listening outside the home was expanded dramatically by the sale of portable transistor radios and cheaper car radios. (In 1951 half of American cars had radios; 80 percent had them by 1965.) This coincidental rise of portable radios and popular music content, combined with the diversion of most adults to television, transformed radio into a predominantly youth-oriented medium. Transistors, developed at Bell Laboratories in the late 1940s, powered the first consumer portable radios by late 1954. Initially expensive to buy and tinny to hear, transistor radios improved in both quality and reliability and grew cheaper over the years. They would eventually spread around the world—especially to developing countries, where they soon replaced more expensive tube-powered receivers, which suffered in tropical conditions.

The FM phenomenon

Frequency modulation (FM), developed by American inventor Edwin Armstrong in the 1930s, was a mode of radio transmission that eliminated most static while improving sound quality. After years of experimentation, Armstrong determined that a wider radio channel (200 kilohertz [kHz] rather than AM’s 10 kHz) was the only effective means of carrying a signal that would transmit the entire range of frequencies heard by the human ear. Because FM varied the frequency rather than the amplitude of the carrier wave (as is the case in AM radio), the FM signal was virtually free of static (an amplitude phenomenon created by electrical storms)—a huge breakthrough that solved a decades-old problem. Although FM was approved in 1941 for commercial operation by the Federal Communications Commission (or FCC, which had succeeded the Federal Radio Commission in 1934), only a handful of American FM stations aired before wartime priorities cut off expansion. Most FM outlets merely duplicated what their AM station owners broadcast, while others offered classical music and other upscale formats, dictated by the high price of early FM receivers that restricted audiences to the wealthy and educated minority. In 1945 the FCC shifted FM service up to frequency bands in the 88–108 megahertz (MHz) range still used today, which increased the number of available channels. Owning an FM outlet was seen by many as insurance for an AM broadcaster if radio broadcasting shifted to FM, as some were predicting.

American noncommercial or educational radio was given reserved FM channels. From a mere 8 FM outlets in 1945, the educational service grew to 85 outlets by 1952, and this number nearly doubled by 1960. But commercial FM service faltered for a time after 1949 as broadcasters focused on developing the more popular television and AM radio services. Offering little original programming for the few expensive receivers available (and thus attracting little advertising income), the service saw hundreds of outlets leave the air. By the mid-1950s, FM service had shrunk to slightly more than 500 stations.

In Europe, however, FM (dubbed VHF, as it was in most countries because of the spectrum it occupies) was soon perceived as a means of reducing horrendous medium-wave overcrowding and interference problems. It also helped serve regions largely unreached by existing stations. As part of the rebuilding of its industry, Germany led Europe in beginning FM broadcasting. The first FM transmissions were on the air by 1949, and most of West Germany was covered with FM signals by 1951. Sale of FM receivers was brisk (some were exported to the United States), partly because television was not a competitor in Germany until 1952. By 1955, 100 FM transmitters were in operation in West Germany. Italy, facing a severe shortage of medium-range frequencies, followed suit, providing its first FM services in the early 1950s. A decade later, multiple FM transmitters were operating in Belgium, Britain, Norway, Finland, Switzerland, and Sweden.

Radio in developing countries

Created by the United Nations in 1947 to help promote educational, scientific, and cultural development, UNESCO quickly became the primary provider of information about the possibilities of broadcast media in the world’s underdeveloped countries, and it funded many experiments involving the more effective educational and cultural use of radio. By the late 1950s radio had rapidly expanded in a large number of countries and colonies that still lacked television service (or had only one station in the capital city). Radio was growing by all measures: hours of weekly programming, the number of radio receivers in use, and the greater availability of service beyond major cities. At the same time, however, 60 percent of the world’s population was said to have inadequate service, since 60 percent of the transmitters and 80 percent of the receivers were located in Europe and North America.

Among developing countries in the postwar period, South American countries provided the best-developed radio systems, in part because the majority of stations were privately owned, thus encouraging investment and expansion and allowing them to be somewhat less affected by changes in government. Furthermore, none had been exposed to World War II’s devastation. Argentine radio offered four national networks, three of them privately owned. Brazilian stations, all of them private, were required to carry a daily government program, but half their time on the air was given over to music. While many countries imported receivers, Chile manufactured enough radios for its own domestic needs. Venezuela combined a state-operated network with privately owned stations, and by the 1950s it was expanding the use of radio in schools.

Asian radio, on the other hand, was characterized in the postwar period by government-controlled stations, with only Japan and the Philippines also allowing commercial outlets to operate. Most stations broadcast in multiple languages, sometimes rebroadcasting popular programs for different language groups. India had one of the world’s largest radio news organizations, providing more than nine hours a day of news for domestic listeners. UNESCO supported an Indian experiment in radio “farm forum” broadcasts to encourage improved agricultural methods. While the number of transmitters in Asia grew threefold from 1950 to the early 1960s, the number of receivers did not grow as quickly, and community listening and the use of radio in schools were thus widespread. Chinese radio was especially dependent on a wired broadcasting system that served cheap receivers that could tune in only one channel.

During this period radio was least developed in Africa, since much of that continent was made up of colonies controlled by Europe. The limited radio service was designed chiefly for European settlers; relatively little was directed to indigenous populations, and in any case the number of available receivers was very low. Independent Ethiopia provided just two hours of radio service daily, using short-wave radio that served a few thousand receivers. South African radio was directed at whites who spoke Afrikaans or English, and there was virtually no service to the huge indigenous black population. As part of a British policy to develop radio in its colonies and to broadcast in native languages, Kenya offered radio service in English, while Nigeria was expanding service to broadcast in 10 African languages. In addition, the BBC in London was increasingly active as a training centre for broadcasters in developing countries. France pursued a different policy in its colonies, encouraging radio broadcasts primarily in French.