Top 40 (radio format)
The Top 40 is a musical hit parade, a list of the forty best-selling singles in a given week. By extension, the term is used adjectivally to refer to pop music in general. The term was first used for a radio format that features repeated plays of a small number of hit records.
Top 40 radio format
Although the concept of the hit parade is older, in the early 1950s, broadcaster Todd Storz was in a tavern in Omaha, Nebraska when he noticed that the patrons repeatedly played only a few songs on the juke box despite a large selection. Storz realized that people liked hearing the hits repeatedly, and developed the first Top 40 programming on New Orleans station WTIK.
Previously, radio stations had programmed in blocks of music, each covering a different style or genre. Top 40 was a response to the rise of television, putting something on radio that wasn't available on TV, and wouldn't be until many years later with the rise of MTV, the cable television version of Top 40.
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 1950s 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
The 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.
Although radio playlists grew considerably longer after the 1970s, the concept of a closely controlled overall sound for a station 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.
For further details of the Top 40, see UK Top 40 and US Top 40.