Top 40

St. James Encyclopedia of Pop Culture, Jan 29, 2002 by Willie Collins

By 1965, disc jockey and program director Bill Drake experimented with programming ideas to transform KHJ in Los Angeles to a Top 40 station, devising the concept of "Boss Radio." This Top 40 format was copied by numerous stations across the country. By 1968, the listening audience for Top 40 began to erode from competition by FM "free form" (later called "progressive" rock) radio. During most of the 1970s, Top 40 did maintain a smaller audience, even as the popularity of disco peaked in 1978. Though Top 40 regained some of its listening audience in 1983, by 1993, mainstream Top 40 disappeared as new appellations, including rock and alternative, were added to Top 40 formats. The number of radio stations identifying themselves as Top 40 also dwindled from 578 to 441. Gavin noted that the strong competition experienced by Top 40 stations brought the ratings down. In addition to competition from other radio stations, MTV (Music Television) launched in 1981, was an immediate success with young viewers. MTV essentially did what Top 40 had purported to do all along, and that was play the hits and give listeners what they wanted to hear.