In 1973, Sonia Orwell broke David Bowie’s heart by refusing him permission to adapt her late husband’s final novel into a rock musical. She had rebuffed every request since the hamfisted 1956 movie version starring Edmond O’Brien, and was never likely to make an exception for a glam-rock dandy, but he was sorely aggrieved. “The whole thing was originally Nineteen-bloody-Eighty-Four,” he said of Diamond Dogs, the feverish post-glam dystopia into which he rerouted his Orwellian dreams. In truth, she probably did him a favour, because the brilliant mess of Diamond Dogs, which cut-and-pasted fragments of Orwell’s novel with William Burroughs’s The Wild Boys and Anthony Burgess’s A Clockwork Orange, was more his style. Bowie never settled for one idea when he could have three. “I get bored very quickly,” he told Burroughs when they met that year.

Bowie was a famously insatiable reader. As a teenager in Bromley he was schooled in the Beats by his older brother Terry. Cocaine-crazed in 1970s America, he would stay up all night inhaling books about the occult from his 1,500-volume portable library. In 1998, somewhat more well adjusted, he wrote reviews for Barnes & Noble. Feeling from an early age formless and incomplete, he rebuilt himself from pieces of the things he loved: not just literature and music but cinema, art, people, places. While the similarly well-read Bob Dylan preferred to veil his sources, Bowie made an exhibition of them – literally so at his touring museum show David Bowie Is, where some of his favourite books dangled from the ceiling like mobiles. He was the star-as-fan and his fandom was promiscuous. When LCD Soundsystem’s James Murphy admitted that he had pillaged his hero’s back catalogue, Bowie replied graciously: “You can’t steal from a thief, darling.” In an interview in 1972, however, he was less cavalier. “Sometimes I don’t feel as if I’m a person at all,” he lamented. “I’m just a collection of other people’s voices.”

Bowie’s vast hinterland is exceptionally fertile ground for writers. I have amassed a shelf full of volumes about the man and his work, many of which have emerged since his death in 2016. It is strange to remember that Bowie’s reputation was once precarious. Destabilised by the global success of 1983’s Let’s Dance, he stumbled into the era of the preposterous Glass Spider tour, his suited-and-booted rock band Tin Machine and new enthusiasms, from drum’n’bass to the nascent internet, which were often read as a fading pioneer’s strained attempts to stay hip. The music press ridicule was excessive – he put out some fine work in the 90s and was right about the internet. But he was certainly not what he is now: infallible genius, genderqueer trailblazer, cultural spirit guide. What has happened since his death is akin to canonisation.

It was only a matter of time before someone wrote a book about his books. The basis for journalist John O’Connell’s enterprise is Bowie’s list of the “Top 100 Must Read Books” , published in 2013 – a connoisseur’s buffet of the obvious and the obscure. Who else’s personal canon would feature Sarah Waters and Eugenia Ginzburg, Spike Milligan and Yukio Mishima, Dante and the Beano? Recurring obsessions include New York, Berlin, Japan, psychiatry, magic, totalitarianism, critical theory and youth cults. Only Orwell and Burgess appear twice.

The bonding agent is George Steiner’s 1971 lecture collection In Bluebeard’s Castle, which introduced Bowie to postmodernism at a crucial juncture and licensed him to make use of everything that interested him. He revelled in “this newly found pluralistic vocabulary, this whole George Steiner-ism of life”. The young Bowie was both a seeker and a hustler, his manic turnover of new ideas driven by a three-fold hunger for spiritual answers, artistic inspirations and commercial gambits. He processed stimuli so fast that he could barely keep up with himself. “I change my mind a lot,” he told Burroughs. “I usually don’t agree with what I say very much.”

O’Connell uses the list as scaffolding for an “alternative biography”, but of course that wasn’t Bowie’s intention. Some of his key texts are absent – no Burroughs, no Brion Gysin, no Aleister Crowley, not nearly enough science fiction – while his fondness for Michael Chabon or Martin Amis tells us nothing much. Sometimes a book is just a good read, even when the reader is David Bowie. Bowie’s Books is therefore tenuously buttressed by phrases such as “might have”, “it’s likely” and “it’s easy to imagine”, along with rib-nudging allusions to Bowie’s lyrics.

O’Connell is a spry and erudite guide when he is arguing that the dolphins in “Heroes” came from the Italian writer Alberto Denti di Pirajno, or locating the spur for the 2014 song “’Tis a Pity She Was a Whore” in Burgess’s Earthly Powers, but he often reaches awfully far. Did Bowie’s troublesome dentistry really mean that he would have “appreciated the important role played by teeth” in William Faulkner’s As I Lay Dying? Do ageing rock stars “feel a bit like” the protagonist of Lampedusa’s The Leopard? O’Connell’s claim that Bowie “presumably enjoyed” the Private Eye strip Celeb is especially dubious. Nobody actually enjoys Celeb. Conversely, we get just three pages on Nineteen Eighty-Four and four on A Clockwork Orange. The scaffolding becomes a cage.

Will Brooker, meanwhile, devotes 20 pages of Why Bowie Matters to unpacking the Orwellian resonances of Diamond Dogs, a section he deftly turns into a bluffer’s guide to post-structuralism. Like his heady exegesis of Bowie’s valedictory album Blackstar, these passages show Brooker at his best, a playful, attentive scholar-fan, but he closes his analysis on an ominous note: “We can learn a lot from his approach; it provides us with a guide for how to incorporate Bowie into our own lives.”

Brooker has incorporated more than most. His 2017 book Forever Stardust documented the year he spent travelling, dressing, reading, listening and even eating like Bowie. This follow-up consists of four essays – on ambition, creativity, sexuality and death – in which close reading alternates with pop psychology, with uneven results. In retracing the singer’s path from suburban obscurity to his first US tour, Brooker does to Bowie what Malcolm Gladwell did to the Beatles in Outliers, which is to reduce a remarkable artistic flowering to a tidy little parable about the virtues of hard work and pluck. “The story matters because Bowie showed us … what an ordinary person can become, with enough tenacity and self-belief. It took him 10 years. If you started now, where could you be in a decade?” Perhaps he could find one of the many industrious dreamers from the 1960s edgelands whose names we never got to know. While it is daft to sentimentalise Bowie as a kind of magic spaceman, it is no better to call him ordinary just because he grew up in Bromley. Brooker closes his book with the gooey suggestion that we should all search for the Bowie inside ourselves. Nothing in Bowie’s reading list indicates that he aspired to become a self-help guru.

What is largely missing from these affectionate, idiosyncratic studies is what really makes Bowie matter: the music. Chris O’Leary’s song-by-song blog project Pushing Ahead of the Dame remains the ne plus ultra of Bowie studies because O’Leary never forgets that Bowie was a singer-songwriter. To see him only as a postmodernist culture vulture is like treating Dylan as a poet who just happened to play guitar. Bowie’s essence can’t be found in words and images alone, but in the snowblind funk of “Fame”, the hysterical repetition of “Rebel Rebel”, the questioning piano chords of “Changes”. He admired Richard Wright but he adored Little Richard.

While scattering autobiographical breadcrumbs throughout the video for his final single “Lazarus”, Bowie told director Johan Renck: “They’re going to have a lot of fun thinking about this.” It’s certainly fun to think about Bowie, but not at the expense of listening to him.

• The Ministry of Truth: The Biography of George Orwell’s 1984 by Dorian Lynskey is published by Picador. Bowie’s Books by John O’Connell is published by Bloomsbury (£16.99). Why Bowie Matters by Will Brooker is published by William Collins (£12.99). To order go to guardianbookshop.com or call 020-3176 3837. Free UK p&p over £15, online orders only. Phone orders min p&p of £1.99.