The first radio series of six episodes (called "Fits" after the names of the sections of Lewis Carroll's nonsense poem "The Hunting of the Snark") was broadcast in 1978 on BBC Radio 4. Despite a low-key launch of the series (the first episode was broadcast at 10:30 pm on Wednesday, 8 March 1978), it received generally good reviews and a tremendous audience reaction for radio. A one-off episode (a "Christmas special") was broadcast later in the year. The BBC was in the practice, at the time, of commissioning "Christmas Special" episodes for popular radio series, and while an early draft of this episode of The Hitchhiker's Guide had a Christmas-related plotline, it was decided to be "in slightly poor taste" and the episode as transmitted served as a bridge between the two series. This episode was released as part of the second radio series and, later, The Secondary Phase on cassettes and CDs. The Primary and Secondary Phases were aired, in a slightly edited version, in the United States on NPR Playhouse.
The first series was repeated twice in 1978 alone and many more times in the next few years. This led to an LP re-recording, produced independently of the BBC for sale, and a further adaptation of the series as a book. A second radio series, which consisted of a further six episodes, and bringing the total number of episodes to 12, was broadcast in 1980.
The radio series (and the LP and TV versions) greatly benefited from the narration of noted comedy actor Peter Jones as The Book. He was cast after it was decided that a "Peter-Jonesy" sort of voice was required. This led to a three-month search for an actor who sounded exactly like Peter Jones, which was, ultimately unsuccessful, leading to the producers having to reluctantly, and expensively, hire Peter Jones as the 'Peter Jonesy' kind of voice originally looked for.
The series was also notable for its use of sound, being the first comedy series to be produced in stereo. Adams said that he wanted the programme's production to be comparable to that of a modern rock album. Much of the programme's budget was spent on sound effects, which were largely the work of Paddy Kingsland (for the pilot episode and the complete second series) and Dick Mills and Harry Parker (for the remaining episodes (2–6) of the first series). The fact that they were at the forefront of modern radio production in 1978 and 1980 was reflected when the three new series of Hitchhiker's became some of the first radio shows to be mixed into four-channel Dolby Surround. This mix was also featured on DVD releases of the third radio series.
The theme tune used for the radio, television, LP and film versions is "Journey of the Sorcerer", an instrumental piece composed by Bernie Leadon and recorded by The Eagles on their album One of These Nights. Only the transmitted radio series used the original recording; a sound-alike cover by Tim Souster was used for the LP and TV series, another arrangement by Joby Talbot was used for the 2005 film, and still another arrangement, this time by Philip Pope, was recorded to be released with the CDs of the last three radio series. Apparently, Adams chose this song for its futuristic-sounding nature, but also for the fact that it had a banjo in it, which, as Geoffrey Perkins recalls, Adams said would give an "on the road, hitch-hiking feel" to it.
The twelve episodes were released (in a slightly edited form, removing the Pink Floyd music and two other tunes "hummed" by Marvin when the team land on Magrathea) on CD and cassette in 1988, becoming the first CD release in the BBC Radio Collection. They were re-released in 1992, and at this time Adams suggested that they could retitle Fits the First through Sixth as "The Primary Phase" and Fits the Seventh through Twelfth as "The Secondary Phase" instead of just "the first series" and "the second series". It was about at this time that a "Tertiary Phase" was first discussed with Dirk Maggs, adapting Life, the Universe and Everything, but this series would not be recorded for another ten years.
The audience survey reaction report at the time actually reported a very split reaction – people hated it, or loved it. The decision to commission the second series was backed by management gut instincts rather than clear metrics.
- Simon Jones as Arthur Dent
- Geoffrey McGivern as Ford Prefect
- Susan Sheridan as Trillian
- Mark Wing-Davey as Zaphod Beeblebrox
- Stephen Moore as Marvin, the Paranoid Android
- Richard Vernon as Slartibartfast
- Peter Jones as The Book