History Radio / AmericanTop40

*** Listing the "droppers" from that week's countdown became a regular part of the show in late 1983; prior to that, Kasem would usually mention how many debuts there were but not the songs that fell out. The practice of listing the "droppers" continued on into ''Casey's Top 40'' and the second generation of ''[=AT40=]'' although Kasem usually listed only the titles of the deleted songs by then and not the artists.

** Several episodes during Casey's original run of the show would feature a substitute host whenever he was unavailable. These would normally range be 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). 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}} conveniently named]] "Missed Opportunity", which debuted at #38. This tradition would carry over to ''Casey's Top 40'', with Elliot, and later David Perry serving as guest hosts.

* The 1980s in particular brought a glut of similar countdown shows intended for CHR and/or adult-contemporary stations, including regular [=AT40=] and [=CT40=] guest host Mark Elliot's ''Weekly Top 30'' (from radio program syndicator Drake-Chenault), John Leader's ''Countdown America'' (later taken over by Dick Clark), ''Top 40 Satellite Survey'' hosted by legendary New York radio personality Dan Ingram, and [[Creator/DickClark Dick Clark's]] ''National Music Survey'' (later taken over by Charlie Tuna).

** "I'm Casey Kasem." A variation, "This is Casey on ''American Top 40''", appeared sporadically.

** The theme and musical sound changed twice more in the late 1980s; the first happened in April 1987, when the show's sound got even more synthetic and grounded in UsefulNotes/{{MIDI}}. This package, done by Firstcom, was a smaller affair with two themes (show theme and hour theme) and four bumpers with the odd bit of production music thrown in every now and again. This package, accompanied by the number callout jingles from 1984's package, would last until 1989, several months into Shadoe Stevens' tenure, when LA-based HLC/Killer Music took over. Along with a new intro and end-of-hour/show theme, featuring a group of singers vocalizing the "American Top 40" riff for the first time in the show's history, HLC/Killer Music put their own spin on the general theme of "evolving with the times", with bumpers now in a range of styles from hip-hop to upbeat pop to hard rock to soft ballads. HLC would update the package one last time in 1992, with a new intro and new end of hour/end of show themes in an even more "'90s" style, plus many of the previous bumpers replaced with a new set that ranged from feel-good mid-'90s "party music" to downright bizarre TotallyRadical sounders with a digitally-deepened voice saying the show's title.

** The theme and musical sound changed twice more in the late 1980s; the first happened in April 1987, when the show's sound got even more synthetic and grounded in UsefulNotes/{{MIDI}}. This package, done by Firstcom, was a smaller affair with two themes (show theme and hour theme) and four bumpers with the odd bit of production music thrown in every now and again. This package, accompanied by the number callout jingles from 1984's package, would last until 1989, several months into Shadoe Stevens' tenure, when LA-based HLC/Killer Music took over. Along with a new intro and end-of-hour/show theme, featuring a group of singers vocalizing the "American Top 40" riff for the first time in the show's history, HLC/Killer Music put their own spin on the general theme of "evolving with the times", with bumpers now in a range of styles from hip-hop to upbeat pop to hard rock to soft ballads. HLC would update the package one last time in 1993, with a new intro and end of hour/end of show themes in an even more "'90s" style, plus many of the previous bumpers replaced with a new set that ranged from feel-good mid-'90s "party music" to downright bizarre TotallyRadical sounders with a digitally-deepened voice saying the show's title.

** The theme and musical sound changed twice more in the late 1980s; the first happened in April 1987, when the show's sound got even more synthetic and grounded in UsefulNotes/{{MIDI}}. This package, done by Firstcom, was a smaller affair with two themes (show theme and hour theme) and four bumpers with the odd bit of production music thrown in every now and again. This package, accompanied by the number callout jingles from 1984's package, would last until 1989, several months into Shadoe Stevens' tenure, when LA-based HLC/Killer Music took over. Along with a new intro and end-of-hour/show theme, featuring a group of singers vocalizing the "American Top 40" riff for the first time in the show's history, HLC/Killer Music put their own spin on the general theme of "evolving with the times", with bumpers now in a range of styles from hip-hop to upbeat pop to hard rock to soft ballads. HLC would update the theme one last time in 1993, in an even more "90s" version of the same style.

** Shadoe Stevens always ended his episodes with "So until we meet again, this is your best friend, D'Shadoe. Bye bye out there."

** As the 1980s rolled around, the music would slowly evolve to fit with the times. The music in use at the time would be supplemented in both 1981 and 1982 by another Dallas company, JAM Creative Productions, who used a far lighter, more melodic tone for their music (used for the hour openers and closers, with bumpers added in for the 1982 package; similar to the sound they utilized for Creator/DickClark's show) than the harder sound employed by the TM tracks. For 1984, JAM would make a full package for the show. Taking cues from the shifts musical trends were taking at the time, this set utilized a mix of SynthPop, {{rock}}, and the company's [[SignatureStyle trademark horn section]] with four individual tracks for the show opening, ending, and bottom and top-of-hour breaks. Along with four sets of bumpers that were each mixed out into acapella and instrumental versions, with both the "The Hits From Coast to Coast" and "Casey's Coast to Coast" taglines used interchangeably for the bumpers leading into commercials. It would be supplemented by commercial bumpers carrying a much heavier synth sound for 1985. Conversely, the intro's opening notes --a rendition of the "Hits From Coast to Coast" tagline -- would switch from futuristic synths to a full horn section in the process.

** As the 1980s rolled around, the music would slowly evolve to fit with the times. The music in use at the time would be supplemented in both 1981 and 1982 by another Dallas company, JAM Creative Productions, who used a far lighter, more melodic tone for their music (used for the hour openers and closers, with bumpers added in for the 1982 package; similar to the sound they utilized for Creator/DickClark's show) than the harder sound employed by the TM tracks. For 1984, JAM would make a full package for the show. Taking cues from the shifts musical trends were taking at the time, this set utilized a mix of SynthPop, {{rock}}, and the company's [[SignatureStyle trademark horn section]] with four individual tracks for the show opening, ending, and bottom and top-of-hour breaks. Along with four sets of bumpers that were each mixed out into acapella and instrumental versions, both the "The Hits From Coast to Coast" and "Casey's Coast to Coast" taglines were used interchangeably for the bumpers leading into commercials. It would be supplemented by commercial bumpers carrying a much heavier synth sound for 1985. Conversely, the intro's opening notes --a rendition of the "Hits From Coast to Coast" tagline -- would switch from futuristic synths to a full horn section in the process.

** As the 1980s rolled around, the music would slowly evolve to fit with the times. The music in use at the time would be supplemented in both 1981 and 1982 by another Dallas company, JAM Creative Productions, who used a far lighter, more melodic tone for their music (used for the hour openers and closers, with bumpers added in for the 1982 package; similar to the sound they utilized for Creator/DickClark's show) than the harder sound employed by the TM tracks. For 1984, JAM would make a full package for the show. Taking cues from the shifts musical trends were taking at the time, this set utilized a mix of SynthPop, {{rock}}, and the company's [[SignatureStyle trademark horn section]] with four individual tracks for the show opening, ending, and bottom and top-of-hour breaks; along with four sets of bumpers (which were each mixed out into acapella and instrumental versions, both "The Hits From Coast to Coast" and "Casey's Coast to Coast" taglines being used interchangeably for the bumpers leading into commercials). It would be supplemented by commercial bumpers carrying a much heavier synth sound for 1985. Conversely, the intro's opening notes --a rendition of the "Hits From Coast to Coast" tagline -- would switch from futuristic synths to a full horn section in the process.

** As the 1980s rolled around, the music would slowly evolve to fit with the times. The music in use at the time would be supplemented in both 1981 and 1982 by another Dallas company, JAM Creative Productions, who used a far lighter, more melodic tone for their music (used for the hour openers and closers, with bumpers added in for the 1982 package; similar to the sound they utilized for Creator/DickClark's show) than the harder sound employed by the TM tracks. For 1984, JAM would make a full package for the show. Taking cues from the shifts musical trends were taking at the time, this set utilized a mix of SynthPop and {{rock}} with four individual tracks for the show opening, ending, and bottom and top-of-hour breaks, along with four sets of bumpers (which were each mixed out into Acapella and instrumental versions, both "The Hits From Coast to Coast" and "Casey's Coast to Coast" taglines being used interchangeably for the bumpers leading into commercials). It would be supplemented by commercial bumpers carrying a much heavier synth sound for 1985, the intro's opening notes --a rendition of the "Hits From Coast to Coast" tagline -- going from futuristic synths to a full horn section in the process.

* ProductionForeshadowing: Kasem didn't host the second-to-last show of his original tenure in 1988. Instead, Music/DarylHallAndJohnOates guest-hosted. That marked the first time the show had a celebrity guest host; previously guest hosts had always been [=DJs=] (though a few, like Bob Eubanks and Wink Martindale, were also famous as game show hosts). Celebrity guest hosts became common in all later editions of the show.

*** Even after relinquishing ''[=AT40=]'' hosting duties to Seacrest, Kasem continued hosting the AC countdown shows until his retirement in 2009, after which the show became an alternate Hot AC version of ''[=AT40=]'' hosted by Seacrest.

** The theme and musical sound changed twice more in the late 1980s; the first happened in April 1987, when the show's sound got even more synthetic and grounded in UsefulNotes/{{MIDI}}. This package, done by Firstcom, was a smaller affair with two themes (show theme and hour theme) and four bumpers with the odd bit of production music thrown in every now and again. This package, accompanied by the number callout jingles from 1984's package, would last until 1989, several months into Shadoe Stevens' tenure, when LA-based HLC/Killer Music took over. Along with a new intro and end-of-hour/show theme, featuring a group of singers vocalizing the "American Top 40" riff for the first time in the show's history, HLC/Killer Music put their own spin on the general theme of "evolving with the times", with bumpers now in a range of styles from hip-hop to upbeat pop to hard rock to soft ballads. HLC would update it one last time in 1992, in an even more "90s" version of the same style.

** As the 1980s rolled around, the music would slowly evolve to fit with the times. The music in use at the time would be supplemented in both 1981 and 1982 by another Dallas company, JAM Creative Productions, who used a far lighter tone for their music (used for the hour openers and closers, with bumpers added in for the 1982 package) than the harder sound employed by the TM tracks. For 1984, JAM would make a full package for the show. Taking cues from the shifts musical trends were taking at the time, this set utilized a mix of SynthPop and {{rock}} with four individual tracks for the show opening, ending, and bottom and top-of-hour breaks, along with four sets of bumpers (which were each mixed out into Acapella and instrumental versions, both "The Hits From Coast to Coast" and "Casey's Coast to Coast" taglines being used interchangeably for the bumpers leading into commercials). It would be supplemented by commercial bumpers carrying a much heavier synth sound for 1985, the intro's opening notes --a rendition of the "Hits From Coast to Coast" tagline -- going from futuristic synths to a full horn section in the process.

** The revival from 1998 would once again update the style to sound contemporary to the music being played. The first two years utilized a package by the Seattle-based [=ReelWorld=] inspired by the music packages by JAM for ''Casey's Top 40''. TM (now TM Century) took over in 2000, providing regular updates to the show's sound to fit with whatever style was popular during the period the package was made in. Though bumper music in general was discarded when Ryan Seacrest took over in 2004, the TM Century package continued to be used on Casey's AC countdowns until his retirement.

** When the show first started out in 1970, the theme accompanying the show's early was a heavy psychedelic SynthPop theme made using Moog synthesizers by Dallas jingle producer PAMS. By the mid 1970s, the theme would be retired for the longest-lasting intro "Shuckatoom", composed by Jim Long at TM Productions in a {{Funk}} style. The theme would last until 1983 and would be joined in 1979 by the "Coast to Coast Fanfare" (or "[[FanNickname Dark Disco]]"), also by TM, done in the style of {{disco}} music of the period.
** As the 1980s rolled around, the music would slowly evolve to fit with the times. The music in use at the time would be supplemented in both 1981 and 1982 by another Dallas company, JAM Creative Productions, who used a far lighter tone for their music (used for the hour openers and closers, with bumpers added in for the 1982 package) than the harder sound employed by the TM tracks. For 1984, JAM would make a full package for the show. Taking cues from the shifts musical trends were taking at the time, this set utilized a mix of SynthPop and {{Rock}} with four individual tracks for the show opening, ending, and bottom and top-of-hour breaks, along with four sets of bumpers (which were each mixed out into Acapella and instrumental versions, both "The Hits From Coast to Coast" and "Casey's Coast to Coast" taglines being used interchangeably for the bumpers leading into commercials). It would be supplemented by commercial bumpers carrying a much heavier synth sound for 1985, the intro's opening notes --a rendition of the "Hits From Coast to Coast" tagline -- going from futuristic synths to a full horn section in the process.

** When the show first started out in 1970, the theme accompanying the show's early was a heavy psychedelic SynthPop theme made using Moog synthesizers by Dallas jingle producer PAMS. By the mid 1970s, the theme would be retired for the longest-lasting intro "Shuckatoom", composed by Jim Long at TM Productions in a big band style. The theme would last until 1983 and would be joined in 1979 by the "Coast to Coast Fanfare", also by TM, done in the style of {{disco}} music of the period.
** As the 1980s rolled around, the music would slowly evolve to fit with the times. The music in use at the time would be supplemented in both 1981 and 1982 by another Dallas company, JAM Creative Productions, who used a far lighter tone for their music (used for the hour openers and closers, with bumpers added in for the 1982 package) than the harder sound employed by the TM tracks. For 1984, JAM would make a full package for the show. Taking cues from the shifts musical trends were taking at the time, this set utilized a mix of SynthPop and {{Rock}} with four individual tracks for the show opening, ending, and bottom and top-of-hour breaks, along with four sets of bumpers. It would be supplemented by commercial bumpers carrying a much heavier synth sound for 1985, the intro's opening notes --a rendition of the "Hits From Coast to Coast" tagline -- going from futuristic synths to a full horn section in the process.
** The theme and musical sound changed twice more in the late 1980s; the first happened in April 1987, when the show's sound got even more synthetic and grounded in UsefulNotes/{{MIDI}}. This package, done by Firstcom, was a smaller affair with two themes (show theme and hour theme) and four bumpers with the odd bit of production music thrown in every now and again. This package, accompanied with the number callout jingles from 1984's package, would last until 1989, several months into Shadoe Stevens' tenure, when LA-based HLC/Killer Music took over. Along with a new intro and end of hour/show theme, featuring a group of singers vocalizing the "American Top 40" riff for the first time in the show's history, HLC/Killer Music put their own spin on the general theme of "evolving with the times", with bumpers now in a range of styles from hip-hop to upbeat pop to hard rock to soft ballads. HLC would update it one last time in 1992, in an even more "90s" version of the same style.

--> '''Casey Kasem:''' Hello again, everybody, and welcome to ''American Top 40''. My name's Casey Kasem, and I'm all set to count down the 40 biggest hits in the U.S.A. According to the official ''Billboard'' survey, these are the records that you're buying and radio stations are playing all over America this week. So let's warm up with our recap of last week's Top Three...

* NothingButHits: The entire premise of the program. Averted in hindsight by the syndicated reruns, featuring hit songs of their day which have long since dropped off the charts and rarely get airplay outside of 80s stations if that.

** The theme and musical sound changed twice more in the late 1980s; the first happened in April 1987, when the show's sound got even more synthetic and grounded in UsefulNotes/{{MIDI}}. This package, done by Firstcom, was a smaller affair with two themes (show theme and hour theme) and four bumpers with the odd bit of production music thrown in every now and again. This package, accompanied with the number callout jingles from 1984's package, would last until 1989 when Shadoe Stevens joined. After which the music changed yet again when LA-based HLC/Killer Music took the sound in a more HipHop-influenced direction. HLC would update it one last time in 1992, again in the same style.
** The revival from 1998 would once again, update the style to sound contemporary to the music being played. The first two years utilized a package by the Seattle-based [=ReelWorld=] inspired by the music packages by JAM for ''Casey's Top 40''. As of 2000, TM (now TM Century) would provide regular updates to the show's sound to fit with whatever style was popular during the period the package was made in.

** "Now as we continue with our countdown of the 40 biggest hits in the U.S.A., I'd like to welcome ___new stations to the AT40 family...*lists new affiliates*"

** As the 1980s rolled around, the music would slowly evolve to fit with the times. The music in use at the time would be supplemented in both 1981 and 1982 by another Dallas company, JAM Creative Productions, who used a far more lighter tone for their music (used for the hour openers and closers) than the harder sound employed by the TM tracks. For 1984, JAM would make a full package for the show, inspired by the music of the time and utilizing more traditional SynthPop sounds with four individual tracks for the show opening, ending and the show's bottom and top-of-hour breaks and four sets of bumpers. The package would be supplemented by additional, heavier synth tracks in 1985, while altering the intro's opening notes --a rendition of the "Hits From Coast to Coast" tagline -- from a futuristic synth sound to a full horn section.
** The theme and musical sound changed twice more in the late 1980s; the first happened in April 1987, when the show's sound got even more synthetic and grounded in UsefulNotes/{{MIDI}}. This package, done by Firstcom (yet another Dallas company) was a smaller affair with two themes (show theme and hour theme) and four bumpers. This package, accompanied with the number callout jingles from 1984's package, would last until 1989 when Shadoe Stevens joined. After which they music changed yet again when LA-based HLC/Killer Music took the sound to a more HipHop-influenced sound. HLC would update the sound one last time in 1992, once again in the same style.

* FormulaBreakingEpisode: The special countdown episodes were still countdowns, but the two "Book of Records" specials (1980 and 1989) dropped the countdown format entirely.
* 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}} conveniently named]] "Missed Opportunity", which debuted at #38. This tradition would carry over to ''Casey's Top 40'', with Elliot, and later David Perry serving as guest hosts.

** Taken to eleven during the Shadoe run of the original show's run, which featured episodes hosted by then-popular pop acts Music/JodyWatley, Music/RichardMarx, Debbie Gibson, and even ''Series/NightCourt'' star Harry Anderson. The current Ryan Seacrest run (Secrest himself having guest hosted during Casey's second tenure on the show) have had several pop stars fill in for him at different points including Music/TaylorSwift, Music/KellyClarkson and Music/LadyGaga, along with actors Creator/NeilPatrickHarris, Creator/HaileeSteinfeld and talk show host Creator/JimmyFallon.
* InvincibleHero: In certain eras when a new song by certain artists debuted you could count on it eventually hitting the Top 5 if not #1, particularly if the song happened to debut on the Hot 100 ''within the Top 40'', which, unlike today, was unusual in the '70s and '80s. Even if you liked the song you had to hunker down and get ready to hear it every single week for the next few ''months'' . Good examples are anything by [[Music/TheBeeGees the Gibb brothers]] in the late 70s or Music/MichaelJackson in the 80s.

* AudienceParticipation: You can vote for your favorite song at [[http://www.at40.com the show's official website]]; the results will be factored into the countdown.

* {{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.

** 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:*]]Complete with acknowledgement of the song's censorship 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.

* EarlyInstallmentWeirdness: Kasem's delivery was more hip and fast-paced in the first year or two, before relaxing by the middle of 1972. Early shows also had several oldies, usually the No. 1 song from a multiple of five years prior to the original airdate, along with other notable songs and album cuts from that week's No. 1 album.

** Taken up to eleven during the Shadoe run of the original run, which featured episodes hosted by then-popular pop acts Music/JodyWatley, Music/RichardMarx, Debbie Gibson, and even ''Series/NightCourt'' star Harry Anderson. The current Ryan Seacrest run (Secrest himself having guest hosted during Casey's second tenure on the show) have had several pop stars fill in for him at different points including Music/TaylorSwift, Music/KellyClarkson and Music/LadyGaga, along with actors Creator/NeilPatrickHarris, Creator/HaileeSteinfeld and talk show host Creator/JimmyFallon.

* NothingButHits: The entire premise of the program. Averted in hindsight by the syndicated reruns, featuring hit songs of their day which have long since dropped off the charts.

* SeriesContinuityError: When "With a Little Luck" by [[Music/PaulMcCartney Wings]] debuted at #17 in 1978, Casey said it was the highest debut in the show's history. Oops! Several songs had already debuted at a higher position, and the record holder was actually "Theme From ''{{Film/Shaft}}''" by Isaac Hayes, which debuted at #9 in 1971.

* ShoutOut: Casey gave one to his own ''WesternAnimation/ScoobyDooWhereAreYou'' character on one show, giving part of the introduction to one song in his "Shaggy" voice.

* 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).

* SpiritualSuccessor: ''[[DuelingShows Casey's Top 40]]'', created the year after Casey left ''[=AT40=]'' and running from 1989-1998. The program even used the "Casey's Coast to Coast!" bumper that had been present in ''[=AT40=]''. The biggest difference was the use of an airplay-only chart from ''Radio and Records'' magazine rather than the Billboard Hot 100.
** Casey even referred to his new show as ''[=CT40=]'' (no relation to the current ''Country Top 40'' country-music countdown show hosted by Bob Kingsley, the original host of ''[=AT40=]'' sister show ''American Country Countdown'') during its first few months on the air, which was reflected in the accompanying commercial bumpers and which quickly drew the ire of ''[=AT40=]'' distributor ABC/Watermark, who sued Westwood One to stop this practice.

* VocalEvolution: Casey's vocal tone shifted several times over the years, which he later acknowledged, though he said it wasn't intentional. In the first few years he had a laid-back, vaguely hipster-ish style, then shifted to a warmer, more friendly approach. His late 70s/early 80s persona has been called "Disco Casey": slick, energetic and enthusiastic. After that he settled into a more avuncular and authoritative style.
** [[{{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, starting with 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.
** 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 known 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=] before getting replaced by another Dallas-based company, TM Century only a year later) 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.

** Taken UpToEleven during the Shadoe run of the original run, which featured episodes hosted by then-popular pop acts Music/JodyWatley, Music/RichardMarx, Debbie Gibson, and even ''Series/NightCourt'' star Harry Anderson. The current Ryan Seacrest run (Secrest himself having guest hosted during Casey's second tenure on the show) have had several pop stars fill in for him at different points including Music/TaylorSwift, Music/KellyClarkson and Music/LadyGaga, along with actors Creator/NeilPatrickHarris, Creator/HaileeSteinfeld and talk show host Creator/JimmyFallon.

** 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:*]]Complete with acknowledgement of the song's censorship 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).

** Often used as an intro to the final hour of the show: "We're [[Baseball/UsefulNotes headin' into the home stretch]] now on ''American Top 40'', counting down the most popular songs in the U.S.A. and getting closer and closer to No. 1."

* AscendedExtra: Ryan Seacrest filled in for Kasem as ''AT40'' guest host a year or so before he took over the reins full time.

** During the Shadoe era, the beginnings of songs would often be repeated (and repeated and REPEATED) in a loop to provide Shadoe with a music bed during his song intro. Songs would also have verses removed/repeated to fit the show's allotted time.