All too often, music biographers are embroiderers of myths. Refreshingly, Rob Chapman's biography of Roger Keith Barrett - the man who became "Syd" in the early 1960s and who founded (and named) Pink Floyd in 1964 - is a settling of scores, rather than a setting of a legend even deeper into stone. As a fan who once saw the Pink Floyd founder in 1972, and admits to having been starstruck ever since, Chapman works hard to humanise this peculiar musician. This is quite an achievement when you consider the bare bones of Barrett's life story - a crash-and-burn three-year career brought to an end by hallucinogenic drugs, followed by 25 years as a recluse, hiding away from the world in London and Cambridge as his former bandmates became the biggest group on the planet.
Chapman's approach to his idol is simple: he has tried to secure as many interviews as possible with friends, girlfriends and relatives. Barrett's youngest sister, Rosemary, who was close to her brother up to the day of his death, recounts their happy upbringing in Cambridge with their pathologist father, Max, and a mother who would let her son invite friends round for a "Sunday joint" - the real meaning of which was lost on other parents. These classmates included the eminent religious historian Andrew Rawlinson and the artist Storm Thorgerson, who later designed the sleeve for The Dark Side of the Moon. All of them provided fuel for Barrett's unusual mind.
A month before Barrett's 16th birthday, his father died of cancer. Chapman points out that writers Barrett loved, such as Kenneth Grahame and Lewis Carroll, lost parents at a similarly young age. He suggests that the pain of bereavement made these men retreat into fantasy worlds. Not long after Max departed, "Syd" arrived, Roger taking his new nickname from a contemporary jazz artist.
From here until the mid-1960s, his transformation is fascinating. Chapman pores over the details of Barrett's development as a painter and his dry-witted letters to his then girlfriend, Libby Gausden, which reveal a boy as sexual and possessive as he was romantic. The top 20 hits he went on to write, such as "See Emily Play" and "Arnold Layne", influenced several leading musicians, among them David Bowie, John Lydon and Blur. Yet Barrett's brilliantly eccentric artistry often had humble origins: for instance, Pink Floyd's first big prog-rock flourish, "Interstellar Overdrive", was inspired by the theme tune to Steptoe and Son.
Slowly but surely, though, the drugs began to do their work. In 1968, Barrett was pushed out of the band. His friend Anthony Stern, who created the light shows for which Pink Floyd became so well known, reasons that LSD accentuated "how absolutely fascinating the . . . interior world really was" for him. This is a melancholy statement, considering how lonely he must have been in his later years.
Chapman shows how Barrett continued to reach out. He explores the text and film sources of Syd's life in the late 1960s, when he was working on the first of two solo albums, and finds many examples of him talking and playing lucidly. He dismantles Nick Kent's 6,000-word article "The cracked ballad of Syd Barrett", published in the New Musical Express in April 1974, which was full of tall tales of Barrett's early output and which began the long mythologising of Syd.
After listing Kent's "numerous factual errors", Chapman allows the writer a chance to defend himself. Kent's flowery response ("the story is more or less true - it exists amidst an infinity of strange tales") speaks volumes about how rock writers disregard the lives of their subjects, using them instead to further their own reputations.
This is something Chapman never attempts to do. Even when taking us through the last 25 years of Roger's life - Barrett's old name returning once his musical life was over - he accords similar respect to the man who spent his last years quietly back in Cambridge, cycling to the supermarket and fending off those who threatened his privacy. Chapman reminds us how unfair it is for fans to feel that they own their heroes. How fitting that his biography does such a good job of letting his hero out into the world, through the voices of those who knew him.
Syd Barrett: a Very Irregular Head
Faber & Faber, 448pp, £14.99
Jude Rogers is pop music critic of the NS.