It has been standard for decades for films and TV shows to have soundtrack albums released. In the last twenty years or so this has extended to video games as well.
A less-tapped market is book soundtracks, although this seems self-evident: films, TV shows and video games have soundtracks as a matter of course, books do not. That makes the official (or semi-official, or even copyright-infringing) book soundtrack something a rarity in the field. But not completely unknown. Here's a few examples.
I Robot by The Alan Parsons Project (1977)
British rock band The Alan Parsons Project conceived of a soundtrack album based on Isaac Asimov's Robots series of science fiction novels and short story collections, particularly the first book, I, Robot, in the mid-1970s. Bandmember Eric Woolfson was particularly enthusiastic for the project and contacted Asimov himself, hoping to make it an official record. Asimov was keen on the idea, but noted that he had sold the media rights to a studio who was planning a big-budget feature film (which ultimately would not be released until 2004, with the most tenuous of connections to Asimov's book), so it could not be an official project but he gave his blessings for a "spiritual tribute" to the book.
For these reasons, the title was adjusted to I Robot (what a copyright difference a comma makes) and specific references to Asimov's universe and characters were omitted, with more general themes related to robots and artificial intelligence instead referenced.
The record did extremely well on release, perhaps helped by being released just days after the film Star Wars, which had re-awoken a hunger for science fiction material in the United States (and, later, in the UK).
Apple Music link.
The King of Elfland's Daughter by Bob Johnson and Peter Knight (1977)
Founded in 1969, Steeleye Span are one of Britain's most successful folk rock bands, still touring today. In the 1970s, bandmembers Bob Johnson and Peter Knight hit on the idea of adapting the classic fantasy novel The King of Elfland's Daughter for music.
Released in 1924, Lord Dunsany's novel has been cited as one of the taproot texts of modern fantasy, featuring political intrigue, war and adventuring in a well-realised secondary world, all more than a decade before J.R.R. Tolkien released The Hobbit. More obscure today, it was much better-known in the 1970s.
Johnson and Knight worked on the album after leaving Steeleye Span, and combined original music with spoken word excerpts from the novel with a full voice cast. Sir Christopher Lee - inevitably a strong fan of the book - was cast as the King of Elfland and also the narrator.
The album was released in 1978 but did not attract a strong critical reception.
Jeff Wayne's The War of the Worlds by Jeff Wayne (1978)
In the early 1970s, Jeff Wayne was best-known as David Essex's producer and arranger, but he felt his composing output had declined and he was no longer as creatively satisfied as he had been earlier in his career. His first project had been composing a score for his father Jerry Wayne's West End musical version of Charles Dickens' A Tale of Two Cities (1966), which had gotten him the gig working with Essex. He had also written advertising jingles and soundtracks.
Wayne disclosed his creative frustration to his father and they decided on a more elaborate version of the success they'd already had with A Tale of Two Cities. They read a number of well-known novels to find an appropriate story and they both felt that H.G. Wells' The War of the Worlds (1897) was suitable. Wayne was inspired to expand the project into a full-on rock opera, and commissioned his stepmother Doreen to write a script whilst he worked on the score. Both were completed in early 1976, with recording sessions beginning that May. Wayne asked Essex to help and he readily agreed.
Wayne composed a completely original score with one exception: the "Forever Autumn" section kept reminding him of a Lego commercial he'd scored, which had turned into a very unexpected hit single in Japan. He re-contextualised the song for the opera. Otherwise all of the music was new. Wayne also realised he needed a strong voice for the narrator. He wrote a letter to Richard Burton, care of the theatre in New York where he was working, and was shocked to get a phone call from Burton's manager heartily approving of the idea and inviting him to fly to the States to record the narration. Burton, not always known to be the most diplomatic actor about the material he worked with, enjoyed the process and complimented Wayne on his dialogue. One possible problem was that Burton refused to have the music playing as he spoke, as he felt it was a distraction, so had to work with Wayne and David Essex on fitting the dialogue into the right spaces by instinct, which he nailed on repeated takes.
With the record complete, Wayne's publishers were baffled and nearly refused to release it, only relenting when Wayne produced a special cut of the album with the songs cut down to traditional single lengths. This allowed them to release two singles - "Forever Autumn" and "The Eve of the War" - to promote the record. CBS UK then got behind the project in a big way.
Jeff Wayne's Musical Version of The War of the Worlds was released in June 1978 and was a surprise hit. To date it has sold more than 15 million copies, making it easily the biggest-selling record on this list, and has generated hundreds of millions of dollars in revenue in live tours and media sales.
Apple Music link.
"The Ballad of Bilbo Baggins" by Leonard Nimoy (1968)
The Songs of Distant Earth by Mike Oldfield (1994)
Mike Oldfield had shot to fame in the early 1970s with his classic Tubular Bells, but had struggled to produce a direct follow-up due to an increasingly sour relationship with Virgin Records. In 1991 he signed with Warner Music, who gave him complete creative freedom and he felt able to rework his original album into Tubular Bells II.
Oldfield discussed his next project with the record label chairman, Rob Dickins, a science fiction fan who was arguably one of the most influential and important figures in British music at the time. Dickins threw up some ideas, including for an album based on Arthur C. Clarke's 1984 novel The Songs of Distant Earth. Oldfield was familiar with Clarke's work but responded more to the title, which he considered evocative, than the novel itself, which he felt was "not one of his best."
Nevertheless, Oldfield flew to Sri Lanka to discuss the project with Clarke and found that Clarke was a fan of his work on the soundtrack to The Killing Fields. Clarke responded well to Oldfield's suggestions and gave Oldfield the creative freedom to open up the book and do some things differently. Oldfield found the recording process taxing, as he felt that his familiar instruments weren't "science fictiony" enough, so he relied more on keyboards and electronic music. At one point, he was so frustrated that he sat down and based out a theme in a few minutes in an absolute rage, and was later astonished that this worked as a process.
Also during recording, Oldfield played the adventure game Myst and was so impressed by it that he included a Myst-like series of puzzles on an enhanced CD-ROM version of the album.
The album was released in 1994 to a middling critical reception, although Clarke gave it his seal of approval.
Apple Music link.
From the Discworld by Dave Greenslade (1994)
From the Discworld - slightly oddly officially called Terry Pratchett's From the Discworld, which may be creatively accurate but not physically - is a soundtrack album assembled by prog rocker Dave Greenslade and released in 1994. It was an official release created with the full approval of Sir Terry Pratchett.
Greenslade was a member for twenty years of British prog rock band Colosseum before embarking on an eclectic solo career that incorporated transmedia art projects (such as the epicly-titled Pentateuch of the Cosmogony). In the 1980s he switched to soundtracks, producing the music for BBC series including A Very Peculiar Practice, Kinsey, Tales of the Unexpected, Wipe Out, Bird of Prey and Gangsters.
Pratchett was a fan of Greenslade's music and Greenslade was a fan of Pratchett's books, and when they met in 1984 they became fast friends. Eight years later, Greenslade was moved to ask to produce music based on Pratchett's Discworld books and Pratchett agreed. Despite not having a huge amount of musical knowledge, Pratchett also made helpful suggestions, such as "This bit should sound like the opening of the Tory Party Conference," and "Can this bit sound grander? Can we add three more full organs?" Greenslade was also committed to making a soundtrack album, not an album of the songs from the books, so alas "The Hedgehog Can Never Be Buggered At All" did not make the cut. "A Wizard's Staff Has a Knob on the End" did make it in, because it had to, but Pratchett and Greenslade did reluctantly take a knife to an extended reprise that sadly made the subtle and delicate subtext a bit too obvious (or possibly it was a bit too long, but whatever).
The most ambitious track on the album was "Small Gods," which attempted to distil the entire novel (arguably Pratcett's finest and thematically richest) into five minutes. The song is especially notable for guest keyboards from a young Rhianna Pratchett.
The soundtrack was released in 1994 and did not set the charts on fire, although it did have a very long tail. A sequel soundtrack was discussed but never made it into the studio.
Additional Discworld music was produced by Mark Bandola and Rob Lord for the first two Discworld video games - Discworld (1995) and Discworld II: Missing, Presumed...? (1996) - whilst Paul Weir took over composing duties for Discworld Noir (1999). Paul Francis and David Hughes composed the music for Sky One's three Discworld TV serials: Hogfather (2007), The Colour of Magic (2008) and Going Postal (2010).
A Soundtrack for The Wheel of Time by Robert Berry (2001)
The Wheel of Time got its own custom soundtrack album in 2001, although this was an outgrowth of an earlier project. In 1999 Legend Entertainment released the Wheel of Time video game, a well-made but somewhat incongruous first-person shooter based on Robert Jordan's fantasy series. Robert Berry and Leif Sorbye collaborated on music for the game and considered releasing it as a stand-alone album, but did not have enough material.
Robert Berry reconceived the project as a soundtrack based directly on the books and repurposed themes from the games and created new music for the project.
Berry had an impressive pedigree. As a guitarist, bassist, vocalist and producer he'd been active on the music scene since the 1970s, working with Hush, Keith Emerson and Carl Palmer and several other bands. He'd also worked on soundtracks and as a session player.
Unlike Pratchett, Jordan did not get involved in the creation of the Wheel of Time soundtrack album and had no contact with the composer.
Apple Music link.
Geidi Primes by Grimes (2010)
Canadian singer-songwriter Claire Boucher - better known as Grimes - released her debut album in 2010. It was a concept album based on Frank Herbert's novel Dune, with the title being a (misspelt) reference to the Harkonnen homeworld of Giedi Prime. Track titles drew inspiration from the book: "Caladan," "Sardaukar Levenbrech," "Zoal, Face Dancer," "Feyd Rautha Dark Heart," and "Shadout Mapes."
Grimes, at the time unknown, released the record in a low key manner, assuming it would disappear without a trace. Instead, it helped propel her towards superstardom, making her later regret some of the most obscure song title choices.
In 2019 Grimes' career came full circle with a return to SF ideas in her fifth studio album, Miss Anthropocene, including songs that will feature in the forthcoming video game Cyberpunk 2077 (due for release in September this year).
Kaladin by The Black Piper (2017)
Kaladin is a soundtrack album based on Brandon Sanderson's novel The Way of Kings (2010), the first in his Stormlight Archive series. The album was created by The Black Piper, a soundtrack collective led by Michael Banhmiller, a veteran of the movie soundtrack industry where he worked on films such as The Jungle Book, Independence Day: Resurgence, The BFG, La La Land and Jason Bourne. Eleven composers eventually ended up working on the project.
Apple Music link.
There are quite a few others out there, from individual songs to full albums to entire subgenres (the Tolkien-inspired music scene could certainly fill an entire article by itself).