Top 40 is a radio format based on frequent repetition of songs from a constantly-updated list of the forty best-selling singles. The term is also used to refer to the actual list of hit songs, and, by extension, to refer to pop music in general.
Although the concept of the hit parade is older, the invention and naming of the Top 40 format is widely credited to Todd Storz, who was the director of radio station KWOH-AM in Omaha, Nebraska in the early 1950s. At that time typical AM radio programming consisted largely of blocks of pre-scheduled, sponsored programs of a wide variety, including radio dramas and variety shows. Local popular music hits, if they made it on the air at all, had to be worked in between these segments. Storz noted the great response certain songs got from the record-buying public and compared it to the way certain selections on jukeboxes were played over and over. He expanded his stable of radio stations, purchasing WTIK-AM in New Orleans, Louisiana, gradually converted his stations to an all-hits format, and pioneered the practice of surveying record stores to determine which singles were popular each week. In 1954, Storz purchased WHB-AM, a high-powered station in Kansas City, Missouri which could be heard throughout the midwest and great plains, converted it to an all-hits format, and dubbed the result "Top 40". Shortly thereafter WHB debuted the first top 40 countdown, a reverse-order playing of the station's ranking of hit singles for that week. Within a few years, Top 40 stations appeared all over the country to great success, spurred by the burgeoning popularity of rock and roll music, especially that of Elvis Presley.
Other broadcasters who contributed to the development of Top 40 radio included Gordon McLendon, who introduced the idea of contests, games, disc jockey patter and jingles, and Bartell Broadcasters, who emphasized local variations in taste on their Top 40 stations.
After Storz, however, the most important innovators were probably Bill Drake, whose "Boss Radio" format put it all together in a powerful package that became the most popular form of broadcasting in the western United States from the late 1960s through the early 1970s and Rick Sklar whose version of the Top 40 format at radio station WABC-AM was also copied by many stations, particularly those in the eastern and mid-western United States such as WKBW and WLS in the same time period.
Top 40 Radio Format
Top 40 was a response to the rise of television. Scheduled block programming could not compete with the new visual medium, so putting something on radio that wasn't available on TV became vital. Although hit music shows such as American Bandstand occasionally appeared, television wouldn't attempt to directly compete with Top 40 radio until many years later with the rise of MTV, the early incarnation of which was a cable television version of Top 40.
The Top 40 format placed less value on genres and artists and concentrated entirely on repetitive play of hits based on research which reported that listeners wanted to "hear all the hits and nothin' but the hits!". Although rock and roll and Top 40 radio grew up together, out-of-genre Top-40 hits include gospel songs ("Oh, Happy Day!" by the Edwin Hawkins Singers), patriotic propaganda ("Ballad of the Green Berets" by S/Sgt. Barry Sadler, novelties ("The Thing" by Phil Harris), and even the "Battle Hymn of the Republic" as performed by the Mormon Tabernacle Choir. Top 40 also spawned the first generation of star disk jockeys, whose between-song patter and connection with the listeners became as important as the songs themselves.
As a format, Top 40 radio waned in the mid-1970s with the expansion of FM radio with its superior sound and more varied programming. Much of the popular audience moved to more sophisticated and targeted formats such as Album Oriented Rock. Radio stations began to specialize in particular types of music rather than playing current hits regardless of genre. The all-hits format has never completely died, however, and has experienced sporadic resurgences on the FM band, though seldom under the Top 40 name. However, the concept of a closely controlled overall sound for a station that originated with Top 40 radio is now dominant in all genres, basically unchallenged except by a few on-air broadcasters like WFMU and a number of World Wide Web Internet radio broadcasters.