History Radio / AmericanTop40

* SomethingCompletelyDifferent: The special countdown episodes were still countdowns, but the two "Book of Records" specials (1980 and 1989) dropped the countdown format entirely.

** EvolvingMusic: The musical styles of the show's jingles and theme music also changed over the years. The program's theme music during the late 1970s and early 1980s (all the way up to the end of 1983) was a disco piece called "Shuckatoom." Which during 1982 through early 1983 would alternate with a different theme for the top and bottom of the hour[[labelnote:*]]during which the number callouts were also remixed to remove the reverb and Moog synth effects used to that point, while new commercial bumpers were recorded[[/labelnote]] and be accompanied by a companion piece in 1977 [[FanNickname nicknamed]] interchangeably as "Coast to Coast Fanfare" and "Dark Disco." A completely new jingle package was introduced in 1984 which featured a more synth-pop style more in line with the hits of the day. The next year saw another rearrangement of the theme song replacing the synth heard at the beginning with a horn section, along with new jingles added to the pre-existing 1984 package. New packages debuted in 1987 by Firstcom[[labelnote:*]]albeit carrying over the number shoutouts from the 1984 package until 1989[[/labelnote]] and 1989[[labelnote:*]]now produced by HLC with Killer Tracks, whose production libraries are better known as the [[MemeticMutation infamous soundtracks]] used by Creator/DingoPictures[[/labelnote]], and the familiar theme was rearranged, once again by HLC and Killer Tracks, for the last time in 1992.

*** The early ''Casey's Top 40'' jingles were not dissimilar to the mid-1980s ''[=AT40=]'' package (a given, as JAM Creative was behind both), but eventually the show added more jingles with a hip-hop/dance or alternative-rock flavor. ''Casey's Hot 20'' used the same jingle package as ''Casey's Top 40'', but the jingles on ''Casey's Countdown'' were softer and more subdued, as befitting the adult contemporary format. The resurrected ''[=AT40=]'' and its accompanying AC shows all used a similar-sounding music package (now produced by Seattle-based [=ReelWorld=]) to ''[=CT40/20=]'' until Ryan Seacrest took over, though Kasem's other shows continued to use the package, with occasional updates, until his retirement in 2009.

** For the majority of its run on the show, Kasem didn't announce the title of Music/GeorgeMichael's "I Want Your Sex" (though it's unclear whether this was because of a personal objection on his part or a [[ExecutiveMeddling corporate mandate from ABC]]. He ''did'' announce it the first couple of weeks, as well as when it fell out of the Top 40 and during the year-end countdown for 1987[[labelnote:*]]and even brings up how the song was censored on many stations both in the US and worldwide[[/labelnote]]. That and the fact that both Casey freely called other songs with the words "Sex" or "Sexy" in their titles, such as The Stray Cats' "She's Sexy and 17" and Pat Benatar's "Sex as a Weapon", and guest host Charlie van Dyke similarly didn't announce the song's title suggests the latter was at least partially in play).

** For the majority of its run on the show, Kasem didn't announce the title of Music/GeorgeMichael's "I Want Your Sex" (though it's unclear whether this was because of a personal objection on his part or a [[ExecutiveMeddling corporate mandate from ABC]]. He ''did'' announce it the first couple of weeks, as well as when it fell out of the Top 40 and during the year-end countdown for 1987[[labelnote:*]]and even brings up how the song was censored on many stations both in the US and worldwide[[/labelnote]]. That and the facts that both Casey freely called other songs with the words "Sex" or "Sexy" in their titles, such as The Stray Cats' "She's Sexy and 17" and Pat Benatar's "Sex as a Weapon", and guest host Charlie van Dyke similarly didn't announce the song's title suggests the latter was at least partially in play).

** For the majority of its run on the show, Kasem didn't announce the title of Music/GeorgeMichael's "I Want Your Sex" (though it's unclear whether this was because of a personal objection on his part or a [[ExecutiveMeddling corporate mandate from ABC]]. He ''did'' announce it the first couple of weeks, as well as when it fell out of the Top 40 and during the year-end countdown for 1987. That and the fact that both Casey freely called other songs with the words "Sex" or "Sexy" in their titles, such as The Stray Cats' "She's Sexy and 17" and Pat Benatar's "Sex as a Weapon", and that guest host Charlie van Dyke similarly didn't announce the song's title suggests the latter was at least partially in play).

*** The early ''Casey's Top 40'' jingles were not dissimilar to the mid-1980s ''[=AT40=]'' package (a given, as JAM Creative was behind both), but eventually the show added more jingles with a hip-hop/dance or alternative-rock flavor. ''Casey's Hot 20'' used the same jingle package as ''Casey's Top 40'', but the jingles on ''Casey's Countdown'' were softer and more subdued, as befitting the adult contemporary format. The resurrected ''[=AT40=]'' and its accompanying AC shows all used a similar-sounding music package, now produced by Seattle-based [=ReelWorld=] to ''[=CT40/20=]'' until Ryan Seacrest took over, though Kasem's other shows continued to use the package, with occasional updates, until his retirement in 2009.

*** The early ''Casey's Top 40'' jingles were not dissimilar to the mid-1980s ''[=AT40=]'' package (a given, as JAM Creative was behind both), but eventually the show added more jingles with a hip-hop/dance or alternative-rock flavor. ''Casey's Hot 20'' used the same jingle package as ''Casey's Top 40'', but the jingles on ''Casey's Countdown'' were softer and more subdued, as befitting the adult contemporary format. The resurrected ''[=AT40=]'' and its accompanying AC shows all used a similar-sounding music package to ''[=CT40/20=]'' until Ryan Seacrest took over, though Kasem's other shows continued to use the package, with occasional updates, until his retirement in 2009.

** EvolvingMusic: The musical styles of the show's jingles and theme music also changed over the years. The program's theme music during the late 1970s and early 1980s (all the way up to the end of 1983) was a disco piece called "Shuckatoom." Which during 1982 through early 1983 would alternate with a different theme for the top and bottom of the hour[[labelnote:*]]during which the number callouts were also remixed to remove the reverb and Moog synth effects used to that point, while new commercial bumpers were recorded[[/labelnote]] and be accompanied by a companion piece in 1977 [[FanNickname nicknamed]] interchanibly as "Coast to Coast Fanfare" and "Dark Disco." A completely new jingle package was introduced in 1984 which featured a more synth-pop style more in line with the hits of the day. The next year saw another rearrangement of the theme song replacing the synth heard at the beginning with a horn section, along with new jingles added to the pre-existing 1984 package. New packages debuted in 1987 by Firstcom[[labelnote:*]]albeit carrying over the number shoutouts from the 1984 package until 1989[[/labelnote]] and 1989[[labelnote:*]]now produced by HLC with Killer Tracks, whose production libraries are better known as the [[MemeticMutation infamous soundtracks]] used by Creator/DingoPictures[[/labelnote]], and the familiar theme was rearranged, once again by HLC and Killer Tracks, for the last time in 1992.

** For the majority of its run on the show, Kasem didn't announce the title of Music/GeorgeMichael's "I Want Your Sex" (though it's unclear whether this was because of a personal objection on his part or a [[ExecutiveMeddling corporate mandate from ABC]]. He ''did'' announce it the first couple of weeks, as well as when it fell out of the Top 40 and during the year-end countdown for 1987. That and the fact that both Casey freely called other songs with the words "Sex" or "Sexy" in their titles, such as The Stray Cats' "She's Sexy and 17" and Pat Benatar's "Sex as a Weapon", and that guest host Charlie van Dyke similarly didn't announce the song's title suggests the latter was in play).

** EvolvingMusic: The musical styles of the show's jingles and theme music also changed over the years. The program's theme music during the late 1970s and early 1980s (all the way up to the end of 1983) was a disco piece called "Shuckatoom." Which during 1982 through early 1983 would alternate with a different theme for the top and bottom of the hour[[labelnote:*]]during which the number callouts were also remixed to remove the reverb and Moog synth effects used to that point, while new commercial bumpers were recorded[[/labelnote]] and be accompanied by a companion piece in 1977 [[FanNickname nicknamed]] "Dark Disco." A completely new jingle package was introduced in 1984 which featured a more synth-pop style more in line with the hits of the day. The next year saw another rearrangement of the theme song replacing the synth heard at the beginning with a horn section, along with new jingles added to the pre-existing 1984 package. New packages debuted in 1987 by Firstcom[[labelnote:*]]albeit carrying over the number shoutouts from the 1984 package until 1989[[/labelnote]] and 1989[[labelnote:*]]now produced by HLC with Killer Tracks, whose production libraries are better known as the [[MemeticMutation infamous soundtracks]] used by Creator/DingoPictures[[/labelnote]], and the familiar theme was rearranged, once again by HLC and Killer Tracks, for the last time in 1992.
*** The early ''Casey's Top 40'' jingles were not dissimilar to the mid-1980s ''[=AT40=]'' package, but eventually the show added more jingles with a hip-hop/dance or alternative-rock flavor. ''Casey's Hot 20'' used the same jingle package as ''Casey's Top 40'', but the jingles on ''Casey's Countdown'' were softer and more subdued, as befitting the adult contemporary format. The resurrected ''[=AT40=]'' and its accompanying AC shows all used a similar-sounding music package to ''[=CT40/20=]'' until Ryan Seacrest took over, though Kasem's other shows continued to use the package, with occasional updates, until his retirement in 2009.

* GuestHost: Often leaning into SpecialGuest at times, as several episodes during Casey's original run of the show would feature a substitute host whenever he was unavailable. These would normally range from radio personalities or voice over artists, including Creator/DickClark, [[Series/TicTacDough Wink Martindale]], Creator/GaryOwens, ACC host Bob Kingsley, and frequent guest hosts and show [[TheAnnouncer Announcers]] Mark Elliot and Charlie van Dyke (with occasionally rotating show announcer Keri Tombazian also subbing in for a week during 1983). With the second-to-last episode of his tenure being hosted by Music/DarylHallAndJohnOates, a fact that didn't escape him when he returned the following week and announced that they just missed out on introducing their new hit, [[{{Irony}} conviniently named]] "Missed Oppertunity", which debuted at #38 that week. This tradition would carry over to ''Casey's Top 40'', with Elliot, and later David Perry serving as guest hosts.

* GuestHost: Often leaning into SpecialGuest at times, as several episodes during Casey's original run of the show would feature a substitute host whenever he was unavailable. These would normally range from radio personalities or voice over artists, including Creator/DickClark, [[Series/TicTacDough Wink Martindale]], Creator/GaryOwens, ACC host Bob Kingsley, and frequent guest hosts and show [[TheAnnouncer Announcers]] Mark Elliot and Charlie van Dyke (with rotating show announcer Keri Tombazian also subbing in for a week). With the second-to-last episode of his tenure being hosted by Music/DarylHallAndJohnOates, a fact that didn't escape him when he returned the following week and announced that they just missed out on introducing their new hit, [[{{Irony}} conviniently named]] "Missed Oppertunity", which debuted at #38 that week. This tradition would carry over to ''Casey's Top 40'', with Elliot, and later David Perry serving as guest hosts.

* GuestHost: Often leaning into SpecialGuest at times, as several episodes during Casey's original run of the show would feature a substitute host whenever he was unavailable. These would normally range from radio personalities or voice over artists, including Creator/DickClark, [[Series/TicTacDough Wink Martindale]], Creator/GaryOwens, ACC host Bob Kingsley, and frequent guest hosts and show [[TheAnnouncer Announcers]] Mark Elliot and Charlie van Dyke. With the second-to-last episode of his tenure being hosted by Music/DarylHallAndJohnOates, a fact that didn't escape him when he returned the following week and announced that they just missed out on introducing their new hit, [[{{Irony}} conviniently named]] "Missed Oppertunity", which debuted at #38 that week. This tradition would carry over to ''Casey's Top 40'', with Elliot, and later David Perry serving as guest hosts.

** Year-end countdowns were usually even longer, usually (but not always) stretching to 100 songs, even with the lack of extras and with many of the songs edited for time constraints (year-end shows were typically presented in two four-hour sweeps with 50 songs each, with a few years during the mid-80s just having the list run continuously for the full 8-hour period).

** ''[=AT40=]'''s countdown of the Top 40 Newcomers of the '80s (acts who didn't chart on the Hot 100 prior to 1980) left out Music/SheenaEaston, despite her having more hits (and bigger hits) than some of the acts who did make the list.

** For the majority of its run on the show, Kasem didn't announce the title of Music/GeorgeMichael's "I Want Your Sex" (though it's unclear whether this was because of a personal objection on his part or a [[ExecutiveMeddling corporate mandate from ABC]]. He ''did'' announce it the first couple weeks as well as when it fell out of the Top 40, and during the year-end countdown for 1987, suggesting the latter was in play).

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 best remembered for the emotional tone with which Kasem would read the requests on air. In addition, Kasem would often pepper the show with music and chart trivia, artist biographical information, introductions to new acts making their first appearance on the show, music news, short features on various musical topics, and other segments that made it more than just a countdown.

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 best remembered for the emotional tone with which Kasem would read the requests on air. In addition, Kasem would often pepper the show with music trivia, artist biographical information, introductions to new acts making their first appearance on the show, music news, short features on various musical topics, and other segments that made it more than just a countdown.

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 best remembered for the emotional tone with which Kasem would read the requests on air. In addition, Kasem would often pepper the show with music trivia, artist biographical information, introductions to new acts making their first appearance on the show, music news, and other features that made it more than just a countdown.

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 best remembered for the emotional tone with which Kasem would read the requests on air.

** The 1974 year-end countdown famously left the No. 1 hit "Can't Get Enough Of Your Love Babe" by Barry White completely out of the top 100, despite four songs that reached No. 1 afterward [[note]]– "Rock Me Gently" by Andy Kim; "I Honestly Love You" by Olivia Newton-John, "Then Came You" by Dionne Warwick and the Spinners; and "Nothing From Nothing" by Billy Preston –[[/note]], some of them placing in the top 30. ([=AT40=] used the Billboard Hot 100 that year, where "Can't Get Enough Of Your Love Babe" is also left out, with no explanation ever given as to why the song fell short, even though several historians have said the song had enough points to place it within the top 100.
** ''[=AT40=]'''s countdown of the Top 40 Newcomers of the '80s (acts who didn't chart on the Hot 100 prior to 1980) left out Sheena Easton, despite her having more hits (and bigger hits) than some of the acts who did make the list.
** Inverted in part several times, particularly in the early years, when Casey would mention a song title but if you weren't paying attention, it's as if the song was ignored. One early example is "Share the Land" by the Guess Who on a 1970 show, left out due to a number of extras and longer songs being played.

** Casey also often answered listener questions on the air about certain chart factoids - for example, which artist had the most million-selling singles; the highest-debuting song in chart history; and so on.
* {{Bowdlerization}}: Music/ChuckBerry'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.
** To clarify, the show itself never removed any songs from the countdown because of content concerns, but allowed local stations to do so if they wanted. They also occasionally created their own in-house edited versions of songs, for content or time purposes (or both, sometimes). Most infamously, they edited "Mind Playing Tricks on Me" by Music/GetoBoys down to a little over one minute. The popularity of records such as that was likely a big reason why ''[=AT40=]'' eventually switched from the ''Billboard'' Hot 100 to a ''Billboard'' airplay-only chart in early 1992, since controversial rap records typically didn't get enough pop airplay to appear on airplay-only charts. (For what it's worth, rap records like "Mind Playing Tricks on Me" and "Me So Horny" never were played by Casey Kasem himself as they didn't appear on the ''Radio and Records'' chart that formed the basis of ''Casey's Top 40''.)

** The show also never played "Cocaine" by Music/EricClapton, even though Billboard listed it as along with its A-side, "Tulsa Time", when the two songs were released as a live single in 1980. Casey only mentioned "Cocaine" the first week "Tulsa Time" appeared on the show.

** Casey Kasem's well-known [[SigningOffCatchPhrase sign-off]] during his years as host: "Keep your feet on the ground, and keep reaching for the stars!"

* ArentYouForgettingSomeone: ''[=AT40=]'''s countdown of the Top 40 Newcomers of the '80s (acts who didn't chart on the Hot 100 prior to 1980) left out Sheena Easton, despite her having more hits (and bigger hits) than some of the acts who did make the list.

** For the majority of its run on the show, Kasem didn't announce the title of Music/GeorgeMichael's "I Want Your Sex" (though it's unclear whether this was because of a personal objection on his part or a [[ExecutiveMeddling corporate mandate from ABC]]. He ''did'' announce it the first couple weeks as well as when it fell out of the Top 40, and during the year-end countdown for 1987).

** Also, during the run of ''Casey's Top 40'', Casey made reference to ''Billboard'' chart data when discussing pre-1973 hits and to ''Radio & Records'' data when discussing post-1973 hits, since ''[=R&R=]'' began publishing in 1973.

** When ''[=AT40=]'' returned in 1998, anytime Casey Kasem referred to songs' chart histories between 1989-1994, he would use data previously aired on ''Casey's Top 40'' instead of data aired on the Shadoe Stevens era of ''[=AT40=]''.

** [[{{Jingle}} The number call-outs]][[labelnote:*]]The majority of them post-1975 being done by [[http://www.jingles.com JAM Creative Productions]], who also did the music package heard from 1984-1987[[/labelnote]] would follow something similar, switching from a full choir-type style until 1975. Then a more shrill-sounding all-female group was utilized for a year before going back to the full voiced choir sound, but with added synths underneath. To a more youthful five-voice group introduced in 1984 that would become the show's main sound, alternating with a similarly newly recorded seven-voice choir depending on the tempo of the song. The Shadoe run further changed them to accommodate a more hip hop style.