It was first broadcast on 3 April 1964 and the eighth series was transmitted in November and December 1973. Humphrey Barclay was the producer until 1968 and from April that year the task was shared by David Hatch and Peter Titheradge.
The first three performers became more famous as The Goodies on British television:
One peculiar aspect of the show was the unchanging sign-off song which Bill Oddie performed as "Angus Prune" which was not a character who ever appeared in the sketches (except in "The Angus Prune Story" aired on 18 April 1966) or, for that matter, anywhere else. Spoof dramas were billed as Prune Playhouse and many parodies of commercial radio (which was only legalised onshore in the UK during this period) were badged as Radio Prune, but the words Angus Prune seemed as random and incidental as the words Monty Python which began on television much later (first transmission October 5 1969). Whilst the BBC radio shows ITMA, Much Binding in the Marsh, Take it from Here and Beyond Our Ken had previously conditioned the audience to accepting a mix of music, sketches and jokes within a 30 minute show, and Round the Horne was currently doing this, ISIRTA (as it was known to its friends), accelerated the transitions and certainly seemed more improvised. It was one of those programmes where you were unlikely to get all the jokes on first hearing so would have to listen to the scheduled repeat (or an illegal tape recording) to discover what you had missed. It thus helped prepare the television audience for At Last the 1948 Show, the Q Series from Spike Milligan and Monty Python's Flying Circus. The only subsequent British radio programmes that approached the pace of ISIRTA are thought to be Radio Active (an endless spoof of commercial radio, starring among others Angus Deayton and Philip Pope; later transferred to television as KYTV); On the Hour (a fierce parody of over-excited current affairs formats by Chris Morris and others; transferred to TV as The Day Today), The Sunday Format and The News Huddlines (Roy Hudd, Chris Emmett, June Whitfield and others). Some of the cast also appear in the radio comedy quiz show I'm Sorry I Haven't A Clue, which was originally a spinoff from ISIRTA but has outlived it by decades.
Since December 2002, examples of ISIRTA can be heard on Fridays at 12.30 and 19.30 hours GMT on BBC 7 (available on the web, digital radio and digital television).