Top 40 radio was an indirect result of the advent of television in the United States, helped along by rock ‘n’ roll. By the early 1950s, more and more people were bringing television into their homes as the primary source of entertainment. At the time, most radio stations, especially the network affiliates, still had their programming day divided up into various separate programs, just as they had since the 1920s, even though many of the networks’ radio sitcoms, game shows, soap operas, and dramas had either been canceled or were now being presented as simulcasts from television. Into the blank spaces on the schedule, the networks or the local stations inserted as filler programs consisting of recorded music. Most of the music heard on the major stations was what would today be termed middle of the road (MOR), generally pop performances recorded within the past five to ten years, with or without vocals, but also including “light” classical music. Jazz, blues, country, and other types of music were mainly heard on smaller independent stations.
In 1953, Gordon McLendon introduced a new format on the radio stations he owned in Texas, most notably 1190 KLIF in Dallas. Recognizing that, instead of listening to radio entertainment programming with rapt attention, people were now mainly using the radio as background entertainment while they were doing something else, he created what came to be known as “formula radio,” which eschewed any kind of block programming in favor of music all day, interrupted for a fast-paced newscast every hour (plus special bulletins at the drop of a hat), and a heavy dollop of promotion of both the music and news, both on the station itself and in the community.
It was a completely different kind of radio, one which could stay in the background fairly easily but also tended to insinuate itself into the foreground. Ratings soared for McLendon’s stations, and other stations nationwide began to implement a similar format.
According to legend, a radio station owner named Todd Storz was in a bar in Omaha, Nebraska with his business partner Bill Stewart, he noticed that people kept playing the same few songs on the jukebox over and over. Storz reasoned that a radio station operating essentially the same way, taking its playlist from a small group of popular songs, would attract listeners. The bar’s jukebox had 40 records in it, which seemed like a good number to Storz, so he cut the playlist at his KOWH in Omaha to 40 popular songs. The experiment worked, and the idea of playing the “top 40” songs, combined with formulaics borrowed from McLendon, spread to Storz’s other stations and was imitated by stations around the country.
Some stations cut their list down all the way down to the top 20, some promoted their dial position by playing the top 63 (or whatever), but whatever the number of songs played by each station, the format came to be known as Top 40.
Simultaneously with the rise of the Top 40 format in the 1950s came rock ‘n’ roll and its quick rise to the top of the music charts, which put it onto the Top 40 stations. As rock evolved, so did Top 40 radio. Now not just the newscasts were fast-paced. So was the music, and then the commercials. Linking everything was the disc jockey, having evolved from a generic announcer into a personality, not just on the air, but making appearances at sponsors’ businesses, station-sponsored concerts, or anywhere the radio station could be promoted. The effect of many Top 40 stations was a frenetic sonic assault, with no pauses between anything, not even for the DJ to take a breath; that was what the jingle featuring the station’s call letters was for. A 30-second commercial would play between every two-and-a-half-minute song, and on and on, with only the DJ intervening to announce another contest, or take a request live on the air, or to throw it over to the newscaster at the top of the hour (or at :55, as many stations had “news five minutes sooner” as a supposed competitive advantage). Although none of this was part of the Top 40 formula per se, it all ended up becoming a part of “Top 40 radio.”
The Top 40 format tended to be first adopted by smaller stations in each city, many of them in the upper reaches of the dial and some even allowed to broadcast only during the daytime hours. It turned out to be popular enough that these stations were now competing effectively against the larger radio stations. Gradually, some larger stations began adopting a Top 40 format, and it was a sign that Top 40 radio had really arrived when, in the early 1960s, the ABC network switched most of the radio stations it owned to a Top 40 format. ABC’s Top 40 stations, especially clear channel powerhouses 770 WABC in New York City and 890 WLS in Chicago, quickly became among the most influential Top 40 stations in the country.
Top 40 radio was a very egalitarian format. A true Top 40 station would play any song that was selling well, which meant the rock music was interspersed with the occasional instrumental jazz piece or Frank Sinatra vocal performance. Even in terms of “rock” music, a bubblegum record would be followed by something psychedelic, which would be followed by a Motown “soul” hit, which would be followed by a surf guitar song.
Top 40 radio also tended to be very locally oriented. Most Top 40 stations had no network news, only locally originated newscasts. More importantly, most stations created their playlists by surveying local record stores, and in many cases, a song that was frequently heard on the radio in one part of the country because it was selling well there never made it onto the radio in another part of the country. This was even true of stations that had the same owner; even the aforementioned WABC and WLS, both big-city radio stations owned by a major media corporation, did not sound alike.
There were many contributing factors to the end of true Top 40 radio, although the biggest nail in its coffin was the growth of FM radio. At first, many FM stations made a conscious effort to sound as little like a Top 40 station as possible, deliberately using a very low-key presentation and broadcasting songs that weren’t played on Top 40 radio, such as album cuts that weren’t released as singles. Then, as radio manufacturers began to include an FM dial as standard equipment along with AM, especially in car radios, more and more people began to tune to FM. The music sounded better in high-fidelity FM stereo.
Top 40 stations began to pop up on the FM dial, although it was a new, more rigidly formatted version called CHR, the product of corporate consultants, with less news, fewer local and regional hit songs, the commercials broadcast in blocks called stop sets, and the DJs at a slightly slower tempo. Most AM Top 40 stations eventually switched formats during the 1970s and 1980s, most to non-musical ones such as all-news or talk.