Syd Barrett, the founder of Pink Floyd who died on Friday aged 60, provided one of rock music's most enduring and confounding legends; some critics thought him a modern-day Rimbaud, others dismissed him as a deranged under-achiever.Decades after he left the group and brought the curtain down on a short-lived solo career with a shambolic performance on a Cambridge stage, myths about rock's most famous recluse continued to flourish. So-called "Syd sightings" were regularly reported in the music press and occasional snatched photos were subjected to detailed scrutiny.Barrett, whose entire recorded output amounted to little more than three albums, had severed his links with the music industry by 1974 and steadfastly resisted all attempts to entice him back. Widely believed to have suffered psychosis, excacerbated by prolific use of hallucinogenic drugs in the 1960s, he retreated to the cellar of his childhood home in Cambridge where he shunned all contact with the outside world.The Barrett legend was fired by half-truths and apocrypha which blended in a spiral of exaggeration until his name became synonymous with drug-induced madness. Fanzines acclaimed his work, and Pink Floyd's own 1975 tribute Shine On You Crazy Diamond fanned the flames still further. Barrett became the most celebrated acid casualty in rock.What is beyond dispute is that Barrett's influence on the early Pink Floyd after their formation in 1965 was immeasurable. He was their singer, lead guitarist and principal songwriter, composing 10 of the 11 songs on their 1967 debut album The Piper at the Gates of Dawn, which cemented the group's reputation as the darlings of London's psychedelic scene. He composed the group's two early hit singles Arnold Layne and See Emily Play; he also gave the group its name.Roger Keith Barrett was born in Cambridge on January 6 1946, the fourth of five children of Dr Arthur Max Barrett and his wife Winifred. His musical nature was encouraged from an early age. Inspired by the skiffle craze of the mid-1950s, he took up the ukulele and by the age of 14 had graduated to the guitar, playing with several local groups before gaining a place at London's Camberwell Art College in 1964 to study Fine Art.It was during this period that Barrett formed Pink Floyd with his former schoolmate Roger Waters, who was studying Architecture with the organist Rick Wright and the drummer Nick Mason. The group's name was an amalgamation of two bluesmen Barrett admired - Pink Anderson and Floyd Council, although he told interviewers that the name was transmitted to him by a flying saucer.Initially little more than a hobby, Pink Floyd metamorphosed from a run-of-the mill blues band playing the usual round of pubs, parties and polytechnics to a burgeoning psychedelic outfit. The change was chiefly inspired by their leader's discovery of LSD, which had become front-page news in Britain as a result of teenagers using morning glory seeds, which contain small quantities of the drug. LSD's hallucinogenic properties now provided Barrett with much of his inspiration, and the group was slowly developing a sound of its own.The Floyd's debut at London's Marquee Club in February 1966, in which the group played layer upon layer of howling feedback, was well received. Signed by the management team of Peter Jenner and Andrew King, the Floyd became the house band at the UFO club in Tottenham Court Road, where their crazed performances and primitive light show became the focus of the underground.But the pivotal figure was Barrett, who seemed to spend most performances with his back to the audience detuning his guitar, or sitting cross-legged at the edge of the stage while his bandmates struggled to accompany him. When Jenner urged the band to drop their R&B repertoire in favour of more original material, Barrett wrote the bizarre Arnold Layne, based on a transvestite from the group's Cambridge days."Both my mother and Syd's had students as lodgers because there was a girl's college up the road," recalled Waters, "so there were constantly great lines of bras and knickers on our washing lines. Arnold, or whoever he was, took bits and pieces off the washing lines."Despite being banned from Radio London, the Floyd's debut disc breached the top 20. "Arnold Layne just happens to dig dressing up in women's clothing," protested Syd. "A lot of people do, so let's face up to reality." The avant-garde poet-musician Pete Brown hailed Arnold Layne as "the first truly English song about English life with a tremendous lyric. It certainly unlocked doors and made things possible that up to that point no one thought were."Instant stardom brought accompanying pressures. On the night of their Top Of The Pops debut, the Floyd sped down the motorway for a gig in Salisbury. The next day they flew to Belfast while the next week saw them performing at Bishop's Stortford, Bath, Newcastle and Brighton. Acclaimed London appearances at the 24-hour Technical Dream event and Games For May concert on the South Bank followed, and the Barrett-penned See Emily Play was a massive hit.Yet by the summer of 1967 Barrett's friends and associates noticed a change. His LSD consumption was now fearsome and his behaviour became erratic. Sometimes he would strum the same note throughout a performance, or fail to turn up altogether."If Syd was innovative at anything it was getting completely and totally out of it," said The Who's Pete Townshend. "Syd was able to get away with it because he could count on most of the audience being totally out of their brains as well."With Emily riding high in the charts, the Floyd cut their debut album The Piper At The Gates of Dawn. Almost entirely written by Barrett, tracks such as The Gnome, The Scarecrow and Matilda Mother and their hypnotic lyrics indicated a yearning for childhood; others such as Astronomy Domine and Interstellar Overdrive were far-out space songs.Although the album was well received, a series of walkouts and temperamental fits, coupled with the fact that the Floyd's third single Apples and Oranges failed to make an impact on the charts, served to hasten Barrett's departure. Following a disastrous tour of America, by which time Barrett's on-stage demeanour bordered on the catatonic, plans were made to replace him with an old Cambridge friend, Dave Gilmour. The Floyd briefly struggled on as a five-piece, before Barrett's break with the band became final.The Floyd's former leader launched his solo career with The Madcap Laughs, a bizarre album described by Melody Maker as "the mayhem and the madness of the Barrett mind unleashed". There was controversy over some tracks that included studio conversations indicating Barrett's confused mental state.Gilmour, who co-produced, said: "We didn't want to appear cruel, but there is one bit I wish I hadn't done in retrospect." Gilmour again took the producer's chair for the album's follow-up, Barrett, which, although it contained beautiful songs, such as Dominoes and Wined and Dined, proved to be Barrett's last (though unreleased material was later collected and issued by record companies).During the making of the album Barrett made a live appearance at London's Olympia - his first since leaving the Floyd. Accompanied by Gilmour and the drummer Jerry Shirley, he tore through four numbers at breakneck speed before abruptly ending proceedings with a mumbled "Thank you and goodnight". His abrupt exit took his bandmates by surprise.By 1972, as Pink Floyd continued to cement their reputation as one of the world's premier rock bands, their erstwhile leader was back in Cambridge, living in the cellar of his mother's home. Barrett, who told a reporter who tracked him down that he was "full of dust and guitars", made a final attempt at a comeback - a project that was curtailed when his ramshackle band Stars played a disastrous one-off gig at Cambridge Corn Exchange.Ironically, during this period of inactivity, Barrett's personal income began to grow, along with his waistline. Fat royalty cheques from various Floyd compilation albums enabled him to stay at swish London hotels, where he spent his time watching television. When Barrett unexpectedly turned up during the recording of Wish You Were Here - a belated tribute - in 1975, his shaven-headed, bloated appearance meant that his former bandmates failed to recognise him.All attempts to coax Barrett back into the studio failed and by 1982 he was back in Cambridge, where he received occasional visits from the curious. In a rare interview (with two French journalists who called on the pretence of returning some laundry), Barrett - who by now had reverted to the name of Roger - insisted: "I'm trying to get back to London but there's a train strike at the moment." In 1992 Atlantic Records offered Barrett $500,000 for new material; the offer went unheeded. He apparently spent his time painting and writing; in 2002 his sister, who had kept an eye on him since their mother's death in 1991, gave him a stereo, but he expressed little interest in Echoes, a compilation of Pink Floyd's recordings.He had written nearly a fifth of the tracks on it, though he had worked with the group for less than a 30th of its existence. He deigned to watch an BBC Omnibus documentary about himself, but found it "a bit noisy".He was unmarried.