A note on history: From AM to FM radio

How music moved to better broadcasting

By Caroline Ho, Arts Editor

 

Regardless of your taste in music, chances are you can find your niche on some FM radio station. The majority of music stations are found on FM radio, because FM, which stands for frequency modulation, is capable of transmitting higher-quality sound than AM (amplitude modification). The not-super-technical explanation for this is that AM carrier waves are a lot more susceptible to interference from things like electronics and other radio waves. AM also has a more limited dynamic range, making FM a superior medium for music, although it took decades for listeners to embrace FM.

AM radio was developed around the late 19th century, and broadcasting took off in the US in the early 1920s, and it became the first mass entertainment medium. Ordinary working-class people could buy radio receivers and listen at home to music, news, comedies, soap operas—and mass advertising. With the explosive growth of the industry came the need for federal regulation, and thanks to these regulations radio broadcasting basically became an oligopoly of a few big networks and companies. The ’20s through ’40s were the “Golden Age of Radio,” and an age of advertising-driven commercialism.

However, the limitations of audio quality with AM radio led inventors to seek a better way of broadcasting sound. FM radio was invented by Edwin H. Armstrong in 1928 and patented in 1933. It was slow to catch on at first because radios in households across America only had AM receivers. Armstrong tried to partner with RCA (Radio Corporation of America) to popularize this new, higher-quality type of transmission, but RCA was eager to protect its existing commercial empire in AM radio and blocked Armstrong’s efforts. Armstrong, undeterred, set up and financed his own FM radios, petitioning the Federal Communications Commission (FCC) to allow FM stations to be started.

Then the US was swept up in World War II, and progress on radio technology halted. After the war, RCA pressured the FCC to change the frequency range of FM radio, so all of the FM receivers that had been previously sold became basically useless. The FCC also allowed simulcasting, the practice of broadcasting the same programs on both AM and FM stations, so networks just aired identical programming rather than create original, FM-exclusive content, and the superior quality of FM wasn’t showcased. Between this and the rise of television’s popularity in American households, FM radio couldn’t hope to compete. In 1954, after years of legal battles with RCA, Armstrong committed suicide.

AM radio continued to rise in popularity in the aftermath of WWII. Although television was taking away some of radio’s listenership, a lot of radio stations adapted by implementing the Top 40 music format—they played the same 40 hit songs again and again. This format was hugely popular, but it also meant that music stations all sounded similar, and song length was limited to about three minutes.

Re-enter the FM radio, which was perfectly suited to the social and political climate of ’60s America. Hand in hand with the hippie movement and anti-Vietnam sentiment was the growth of rock and roll, and while this new genre found some popularity on AM stations, the derivative Top 40 format limited musical innovation. FM stations were willing to play longer songs and new artists, and FM became the progressive platform for musical experimentation and discovery. The FCC also changed the laws to restrict simulcasting in 1967, another prompt for original programming on FM waves.

Throughout the ’60s and ’70s, FM firmly established its footing as an alternative to AM broadcasting. A lot of stations were run freeform, which meant the DJ basically had free rein over what to play, and many of these stations were also commercial-free. By the end of the ’70s, over half of radio listeners in the US were tuning in to FM stations.

FM had become the unquestionable arena for music, while AM airspace was mostly left to talk shows and news broadcasts. Many people thought that the increase of music on radios would be bad for the recording industry, but the opposite turned out to be true. Hearing songs on the radio prompted people to purchase more records and expand their tastes. FM stations branched out into more and more genres—pop, country, R&B, world, classical, and every other style found new audiences on FM airwaves.

Radio is still a popular and fantastic medium for finding new music and requesting your old favourites. But the same drive for innovation and higher-quality broadcasting that led to FM radio might well lead to its replacement. Satellite radio and digital radio have been available since the 2000s, and with the increasing prominence of internet radio and streaming services such as Pandora, it’s hard to say what the future holds for FM radio.