''Keep your feet on the ground, and keep reaching for the stars.''
->-'''CaseyKasem'''

''American Top 40'' is a weekly, [[LongRunner long-running]] (1970-present, with a three-year hiatus in TheNineties) syndicated radio program, originally hosted by CaseyKasem and currently hosted by RyanSeacrest, which counts down the [[ExactlyWhatItSaysOnTheTin forty most popular]] radio songs in the United States.

In addition to playing the week's most popular songs, ''[=AT40=]'' frequently included various extra segments. Perhaps most famous among these was Kasem's "Long Distance Dedication": a write-in request from a listener for a particular song, always sentimental in nature, typically directed at a person the listener had not seen in a considerable amount of time (such as a long-distance romantic couple, wife to overseas-based military husband, someone's birth parent on the other side of the country, etc). These particular segments were probably best remembered for the almost {{narm}}ish tone with which Kasem would read the requests on air.

In 1988, Kasem left the show and was replaced by ShadoeStevens. The change, as well as an altered format, went over poorly, and ''[=AT40=]'' was eventually cancelled in 1995. Kasem, though, had in the meantime started up a [[DuelingShows rival program]], ''Casey's Top 40'', and eventually managed to acquire the rights to the ''American Top 40'' title, and the show was UnCancelled in 1998. Kasem subsequently retired from the program in 2004; Ryan Seacrest took over hosting duties and helms ''[=AT40=]'' to this day, though on an especially busy week for [[JackOfAllTrades the host/producer/cable network owner/''Today Show'' contributor]], a guest host (usually a top-charting artist) will do the show for Seacrest instead.

Song-ranking data was originally derived from ''Magazine/{{Billboard}}'' Magazine's "Hot 100" pop/rock singles chart before switching over to ''Radio and Records'' (which Kasem had used in his competing program) in 1998. Currently, songs are ranked by data from Mediabase.

In the mid-1980s, ''American Top 40'' also had a MusicVideo equivalent: ''America's Top 10'', which was basically the last hour of the radio program -- that is, the ten most popular songs on the ''Billboard'' chart -- translated to television, using clips from the songs' videos, natch. Other similar programs have included:
* ''Weekly Top 40'', hosted by radio personality RickDees;
* ''Casey's Top 40'', hosted by Kasem himself when he left ''[=AT40=]'' in 1988;
* {{MTV}}'s (later {{VH1}}'s) ''Top 20 Video Countdown''.

Reruns of the program, mostly from the mid and late '70s, are syndicated weekly on "oldies" stations, typically late Saturday night or early Sunday morning.

!!''American Top 40'' provides examples of:
* {{Bowdlerization}}: [[ChuckBerry Chuck Berry's]] "[[IntercourseWithYou My Ding-A-Ling]]" was replaced with a different song in several markets when it reached #1 in 1972, and reruns of those weeks' programs have featured a different song in the #1 position in certain markets.
* CatchPhrase: "Keep your feet on the ground, and keep reaching for the stars!" in the Kasem years.
* DuelingShows: Rick Dees' ''Weekly Top 40'' and, ironically enough, ''Casey's Top 40'' in the early 1990s. For the MusicVideo side of things, ''Top 20 Video Countdown'' for ''America's Top 10''.
* TheEighties: When the show was arguably at the height of its power, although it actually started in TheSeventies.
* LongList / TopTenList: Forty songs, plus a couple of extras, in four hours (originally three).
* LongRunner: The program debuted in 1970 and has been going strong ever since. Well, except for that hiatus in the mid-1990s.
** UnCancelled
* NothingButHits: The entire premise of the program. Averted in hindsight by the syndicated reruns, featuring hit songs of their day which have been all but forgotten by now.
* PreviouslyOn: Starting in February 1979, Kasem played back the top 3 songs from the previous week's show to [[OpeningNarration lead off the countdown]]. This segment eventually would be shortened to feature just the No. 1 song of last week, and by the end of Kasem's original run (in 1988) and on into the Shadoe Stevens-era, the host would simply announce the songs at and near the top of the charts before beginning the show.
* RearrangeTheSong: Some songs would be cut in half to control the show's running time; this typically happened to songs that were on their way down the charts.
* SpinOff: ''Radio/AmericanCountryCountdown'', a country music-version of ''[=AT40=]'' that premiered in 1973 and is still going strong today. The current host is Kix Brooks (one half of the long-running duo Brooks & Dunn); before him were original host Don Bowman (who once guest-hosted ''[=AT40=]'') and later, Bob Kingsley (the host at the height of ACC's run).
** QuietlyPerformingSisterShow: See above. ACC is radio's longest-running, continuously produced syndicated program, outlasting ''[=AT40=]'' (whose current run dates from 1998, the year it returned from a three-year hiatus).
* SuspiciouslySimilarSong: Through the years, a few of the commercial bumpers, most notably, a 1977 cue styled after the Starlight Vocal Band's "Afternoon Delight."
* WholeEpisodeFlashback: A 1975 episode, celebrating the show's fifth anniversary, was a rebroadcast of the very first [=AT40=] from July 4, 1970. The only difference was Kasem occasionally inserting a bumper reminding listeners that this was indeed a program from 1970, and pre- and post-show remarks.
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