American Top 40: The original version of the second-ever broadcast, aired July 11, 1970 (and featuring the chart for July 18) is rumored to be lost; however, some insist that a "reconstituted" version, featuring clips from the July 4 show (AT40's debut, incidentally) and the July 25 program were used to create a "new" July 11, 1970 show. All other episodes from the original 1970-1995 run are known to exist.
Repeats of Casey Kasem-hosted American Top 40 shows, from July 1970 through August 1988, are broadcast as part of two different radio programs: "AT40: The 70s" (featuring 1970-1979 shows) and "AT40: The 80s" (focusing on the 1980-1988 episodes). Both programs are distributed by the Premiere Radio Network. As both packages include Casey Kasem's name in the title (i.e., "Casey Kasem's 'American Top 40': The 80s"), it is not likely that shows hosted by either the occassional guest host or by latter-day host Shadoe Stevens will be aired anytime soon. (Stevens took over for Kasem after he departed ABC Radio Network in August 1988, and hosted AT40 for the rest of its original run; the apparent exclusion of August 1988-December 1989 shows in the 80s package could easily be resolved by the pre-show announcer simply stating that said program aired after Kasem's departure and Stevens taking over the hosting role.)
Although few, if any repeats, have been aired since their original airings, it is believed all shows from AT40's country music sister program, American Country Countdown, exist. 1973-2006 has been digitally remastered by Charis Music Group. ACC began airing in October 1973, and has been hosted by Don Bowman (1973-1978), Bob Kingsley (1978-2005) and Kix Brooks (2006-present), with Kingsley starting another countdown show of his own, Bob Kingsley's Country Top 40.
The improvised radio sitcom The Masterson Inheritance has The Marooned Mastersons, an unbroadcast episode recorded back-to-back with the last normal episode, though judging by the performer's comments it was never intended to be aired anyway. They quickly made doubly sure of this by sending the story into very un-Radio 4 territory, including homosexual incest and a plan to use someone's enormous penis as a banana boat to escape the island, only for him to die of massive blood loss after they tried to christen their 'ship' and the champagne glass shattered. The episode eventually made its way onto the internet.
Most of the episodes of The Goon Show's first four series were erased, which means that almost none of fourth Goon Michael Bentine's episodes survived. (He left after Series 2.) Some of the missing Series 4 stories would be remade for the overseas-broadcast-only "Vintage Goons" series, which has survived.
Ten early episodes of Just a Minute (six from 1968, three from 1969, and one from 1974) have no known surviving recordings. Additionally, most episodes from before 1990 only exist in the Transcription Services editions for international broadcast (The BBC junked most of their original tapes, but The ABC have a nearly complete set of TS tapes), trimmed by around three or four minutes each and sometimes with rounds spliced from other episodes featuring the same panel.
Schadenfreude, by the comedy troupe of the same name, parodied this trope with its missing Episode 39, supposedly removed due to offending someone they joked about in the show. The troupe would again use Episode 39 as the justification for its reunion show, claiming that, by skipping an episode, it violated its contractual obligations to NPR, and had to team back up for one last show.
The radio version of Hancock's Half Hour ran for 102 episodes across six series between 1954 and 1959. Of these, 31 are missing, including three episodes of the second series when Harry Secombe stood in for an unwell Tony Hancock. Secombe's fellow GoonsPeter Sellers and Spike Milligan also made guest appearances in separate episodes in the first series; both of the episodes in question are now lost. See Live-Action TV for the TV episodes lost.
BBC Radio's Educating Archie was primarily a showcase for ventriloquist Peter Brough and his dummy Archie Andrews, but it also launched or boosted the careers of a number of comedians and performers including Tony Hancock, Benny Hill, Dick Emery, Bernard Bresslaw, Harry Secombe, Bruce Forsyth, Julie Andrews, Beryl Reid, Hattie Jacques, Sid James, Warren Mitchell, and Max Bygraves, while the writing staff included such talents as Eric Sykes and Marty Feldman. It ran for eight series from 1950 to 1960 for around 200 episodes; only ten are known to survive, as well as a special made for Australian radio in 1957.
Beyond Our Ken was the first of two BBC Radio sketch series to star Kenneth Horne, with a supporting cast comprising Kenneth Williams, Hugh Paddick, Betty Marsden, and Bill Pertwee. It ran for seven series between 1958 and 1964 for a total of 123 episodes, of which 24 are missing. Its Spiritual SuccessorRound the Horne (starring the same five core cast members) survives intact.
There was a 13-episode BBC Radio adaptation of The Lord of the Rings in 1955-56 which no longer survives. A 1960s adaptation of The Hobbit only survived as an off-air recording (fortunately of good quality), without individual episode credits.
As late as 1984 The BBC wiped the pilot episode for a planned Dads Army radio sequel, It Sticks Out Half a Mile, because Arthur Lowe sounded drunk. He was in fact terminally ill. The series was recast with other Dads Army actors and 13 episodes were made. Astonishingly, most of the series was also wiped - the last known major BBC purge. The pilot and all the lost episodes have been recovered from domestic recordings of varying quality.
Adventures in Odyssey has several, mostly due to the character known as "Officer Harley", a rather buffoonish policeman. Parents thought the character would be a bad impression on the police force, so the charcter was removed. The trope is subverted as some of the episodes reair with Harley edited out of the episode or replaced with another character, such as Eugene Meltsner, but there are several episodes which really are missing, because of Harley being too important of a character or controversial issues, such as abortion.
There's another episode called "Lights Out At Whit's End", which hasn't aired since it first did, not only because of Harley, but also because it was just too...odd, according to Word of God. Ever heard Whit and Tom Riley rap? The episode was available to listen online at the show's website, but seems to have been taken down.
Dick Barton — Special Agent was a popular adventure series which ran on BBC Radio from 1946 to 1951.note It is widely perceived as having been axed by BBC executives due to its sensationalism in favour of the more sedate rural soap opera The Archers, which has been on the air ever since. Of the 711 episodes, only three were preserved by the BBC, as well as a handful of clips. However, in February 2011, 338 episodes were recovered from the National Film and Sound Archive in Australia; though they are re-recordings with a cast of Australian actors rather than copies of the British originals, they use the same scripts and music cues.
Many episodes of Fred Allen's various shows are not known to exist (although some have come to light in recent years). Notably, the original episode that began the Fred Allen-Jack Benny feud does exist, but only the East coast feed. The West coast feed, in which Allen's ad-libbed insults of Benny were apparently much more elaborate and hilarious is apparently gone. The relative few episodes of Fred Allen's shows that are still available compared to Jack Benny's may explain in part why Benny is much better remembered today.
The Marx Brothers radio series Flywheel, Shyster, and Flywheel, which aired as the Monday programme on NBC's Five-Star Theater for 26 episodes in 1932-33, was believed completely lost until the discovery of the scripts of all but one episode in the Library of Congress in 1988, and the discovery of recordings of fragments of Episodes 24 and 25 and the complete Episode 26 in 1996. The BBC adapted some of the surviving scripts and aired them on Radio 4 between 1990 and 1992.
Many episodes of the original 1998 XFM series of The Ricky Gervais Show (often known as Series 0), which took place between January and August 1998 are lost. The reason is that they were not very well known at that time, and the show only ran for a few months, and aired on the unusual time of 4PM-6PM on Sundays. There are two known complete episodes and several tapes worth of compiled material from other shows. What is notable about these shows is that the duo had not met Karl Pilkington yet.
Their second XFM Series (often known as Series 1 because it's the first to feature Karl) began in September 2001, only recordings of shows from 10th November onwards circulate. Thus about 9 shows are missing. This series is the first time they ever broadcast with Karl Pilkington as a cohost of the show. It is more likely than not that somebody did tape the previous two months as the duo were well known from The Office at the time, but that for whatever reason they are not available online yet (or maybe are in collectors' circles).