Co-creator Casey Kasem hosted the original American Top 40 from its inauguration, until August 6, 1988.
The show usually started out with this introduction: Here we go with the Top 40 hits of the nation this week on American Top 40, the best-selling and most-played songs from the Atlantic to the Pacific, from Canada to Mexico. This is Casey Kasem in Hollywood, and in the next three hours, we’ll count down the 40 most popular hits in the United States this week, hot off the record charts of Billboard magazine for the week.
Most segments of the show included two countdown songs. The second song in the segment would usually be introduced by Kasem with a brief story connected with the song, which could be about its performer, its composer, or a random bit of trivia. Kasem would often lead into the commercial break preceding the segment with a brief preview of the story, sometimes even giving away the song title or artist. The top-ranking song on the chart always was introduced with one of these stories, which would be followed with a drum roll and the final reveal. Besides the countdown of the top songs of the week, who can forget about “The Long Distance Dedication”?
As of 2019, shows from the 1970s and 1980s are airing continually, without commercials, on the iHeartRadio station “Classic American Top 40”. Most of iHeart’s branded stations utilize an HD Radio subchannel in one of their markets to originate their app-only stations which carries it over-the-air in that market.
As of April 2020, rebroadcast shows are currently aired on 200 radio stations in 7 countries and every U.S. state except Montana. Foreign rebroadcast shows are heard in four of the eastern provinces of Canada, as well as the American Forces Network, Australia, Bangalore, Berlin, Aruba, Hyderabad, Mozambique, and the United Kingdom.