Dueling Shows: Rick Dees' Weekly Top 40 and, ironically enough, Casey's Top 40 in the early 1990s. For the Music Video side of things, Top 20 Video Countdown for America's Top 10.
Cluster F-Bomb: Casey Kasem was known for attention to detail and perfection, and he would become annoyed or sometimes outright angry if something didn't go right. This was played to perfection in September 1985, when taping an episode that had what's been referred to by fans as the "Dead Dog Dedication." In that episode, the uptempo dance song "Dare Me" by the Pointer Sisters was to be followed by a Long Distance Dedication from a listener wanting to eulogize his beloved pet dog (which had recently died) with the ballad "Shannon" by Henry Gross. As Kasem was reading the letter during the original take, he snapped and went into a profanity-laced tirade (including several f-word utterances) about how he believed a song about death was inappropriately slotted after a dance song. Kasem later calmed down and re-recorded the take, and of course the rant never made it to air, but the original take was preserved on tape and years later became popular through bloopers specials and sites such as YouTube.
Of course, this is not the only time Kasem lost his temper while taping AT40. Another clip circulates on YouTube where he became irritated at having to record individual station promos for station affiliates, believing it to be a waste of time. Included between takes were several words and commentary about the towns served by the affiliates fit only to be heard by a sailor.
There's also the outtake where he objects to the detailed biography of U2 he was given to read when "Pride (In The Name of Love)" hit the Top 40. "These guys are from England and who gives a ***?!"
Kasem even used his Shaggy and Robin voices a few times on the show, and was heard for several years in the late 1970s and early 1980s on NBC, pitching upcoming shows and recording commercial bumpers on the network's Saturday morning block.
Missing Episode: The master tape for the final hour of the second-ever episode (July 11, 1970) has disappeared.
Screwed by the Network: American Top 40's production company, Watermark, was purchased by ABC Radio in 1982. Much of the reason AT40 went off the air in 1995 was because it was getting beaten in the ratings by Casey's Top 40 and The Rick Dees Weekly Top 40. But both of those shows existed because of questionable moves by ABC regarding American Top 40. When ABC insisted that AT40 affiliates start airing other ABC shows and commercials, many of them dropped the show. One of the stations, KIIS-FM in Los Angeles, had their morning DJ Rick Dees start his own countdown show, which soon went into syndication and was quickly picked up by other former AT40 stations. Then when Casey Kasem's contract came up for renewal in 1988, ABC (who reportedly was eager to bring in a younger host) turned down his salary proposal, so Kasem left to start another show.