Davy Graham: Virtuoso guitarist at the heart of the British folk revival whose playing influenced a generation

The guitarist Davy Graham was one of those seminal talents who change the way music is made. His invented guitar tunings were copied by players all over the world and one of his own pieces, "Anji", provided a soundtrack for the Sixties. Folkies listened to him in amazement and blues players with envy. His records were found on the floors of rock groups' Transit vans, in the festering cubby hole that was the band room of Ronnie Scott's "Old Place", and in the more commodious environs of orchestral players' dressing rooms.

He was as omnipresent as that compulsive opening riff to "Anji" (which recently featured as the opening theme to BBC 4's Folk Britannia series in 2006). One moment he'd be at the Festival Hall backing Shirley Abicair, the next he'd be on his way to India, Greece, Turkey or North Africa looking for answers to musical problems of which only he could conceive. He was "already returning from Tangier when the rest of us were still thinking in terms of Brighton Beach," said the guitarist John Renbourn.

Graham incorporated music from many traditions into his repertoire; he arguably invented the genre of "world music" years before the term was coined. There are few musicians playing today who don't acknowledge their debt to Graham, from folkies like Martin Carthy to heavy metal bands like Led Zeppelin. "I owe him," said Carthy. "We all do. He kicked the door down."

David Graham (he was known as Davey as well as Davy) was born in Leicester in 1940 to a Guyanan mother and a Scottish father. He lost the sight in his right eye after falling on a pencil in the playground, a loss he associated with the development of his extraordinary ear and something approaching an eidetic memory where music was concerned. In 1952, when Davy was 12, a neighbour first demonstrated a guitar to him by playing a pavane – by the end of the afternoon the boy could play the piece perfectly.

It wasn't until he was 16 that he acquired a guitar of his own but just a year later he was playing tough pieces like Big Bill Broonzy's "House Rent Stomp". As a teenager he made a stunning impact on bohemian London. Turning up at 50 Pearman Street, a crash pad near Waterloo for out-of-work musicians and artists, he greeted everybody with the formal politeness that was his trademark and began to play an original piece based on a Broonzy line. All of us in that decrepit room felt the world change. In that twilight of the skiffle boom, Graham made Pearman Street's population immediately redundant. Here was a player who married Bill Broonzy and Charlie Mingus, whose questing mind took the whole of music as a resource for the guitar, and made something new and startling, yet extraordinarily accessible.

Failing to make a living or at that point secure any interest from record companies, Graham took off for the continent (in the company of my wife). He busked the cinema queues and the Metro in Paris, played up and down the French Riviera and for Elizabeth Taylor's parties, and visitied Greece, Italy and Tangier.

Back in England he appeared in Ken Russell's 1959 BBC Monitor documentary From Spain to Streatham (also known as Guitar Craze), playing an outrageously original contrapuntal blues, followed by "Cry Me a River". He worked with the blues musicians Alexis Korner and John Mayall and the singer Shirley Abicair, and had a residency in the then fashionable Nick's Diner in Fulham. He also made another film appearance, in Joseph Losey's The Servant (1963).

In 1961 he wrote "Anji", named after a girlfriend of the time. Recorded for Topic, it became the guitar piece that everyone struggled with and then failed to master. The sensation that "Anji" caused among musicians came to the attention of Decca, who signed Graham for a series of albums. The first, Folk, Blues and Beyond (1964) was wildly acclaimed, with The Sunday Times naming it "folk record of the year". The following year he collaborated with Shirley Collins on the critically acclaimed Folk Roots, New Routes (reissued in 1999). Other albums had less impact, although they all contained irreplaceable tracks. Listening to the recordings today one has a sense that the producers didn't know quite what to do with this boundary-ignoring talent.

His music defied categorisation. There was no room in the tightly knit modern jazz world for Graham's abilities, although several recordings show him heading in that direction. Much of his playing was blues based, though he transcended that particular idiom. It was the oft-maligned folk clubs, receptive to wacky instrumental talent, that gave him a home. In some ways he was the folk world's first postmodernist, taking influences from everywhere. The whole of music for him was simply one vast resource for the instrument whose servant he was.

Graham changed the way people thought about the guitar. He invented a modal tuning system called DADGAD, which is today used by many playing Scottish or Irish music. A stunning example can be found in the extraordinary reading of the Irish tune "She Moved Through the Fair / Blue Raga" on the Rollercoaster CD After Hours at Hull University, released in 1997 but recorded in 1967 – at one o'clock in the morning after he'd already played a gig at the university folk club.

Over the years, illness took its toll and for whole periods Graham was in semi-retirement, punctuated by sporadic reappearances. In the Seventies he seemed set for a major comeback with recordings for Stefan Grossman's Kicking Mule label. The 1977 album The Complete Guitarist illustrates his eclecticism, featuring a Horace Silver tune, Renaissance music, Irish song, Vaughan Williams and Robert de Visée's Prelude from the Suite in D minor. It seemed odd to some that he did not include any North African or Indian music, but typically this was because he was learning the appropriate instruments, including the sarod and the oud, and didn't feel he was up to standard on them.

A further absence because of health problems followed the Kicking Mule period and for a while it seemed possible that he would be forgotten to all but musicians. But in 1997 the issue of After Hours created a fresh wave of interest and most of his classic albums became available again, including the seminal Folk Blues and Beyond, The Guitar Player (1963) and All That Moody (1976). A compilation, Fire in The Soul, was released in 1999.

The promise of this period was never totally fulfilled, although there were a number of impressive appearances, including at the Cambridge Folk Festival and in Edinburgh. Recently, a new manager had begun to organise tours but Graham's final illness made further public appearances impossible.

Graham never understood that his mind worked differently from others', that he marched to the beat of a different drum. The revolution he started was as much conceptual as technical; he thought about things in a different way and wasn't bound by any musical preconceptions. Dave Swarbrick, Fairport Convention's fiddle player summed it up: "There was nobody capable of doing what Davy Graham was doing, or even dreaming that it could be done."

In 2005, he was the subject of a BBC radio documentary, Whatever Happened to Davy Graham? , and the following year he was one of the artists featured in BBC 4's series Folk Britannia.

John Pilgrim

David Michael Gordon Graham, guitarist, arranger and composer: born Leicester 26 November 1940; two daughters; died London 15 December 2008.