John Martyn emerged from the British folk scene in the late 1960s to make some of the most hauntingly evocative and mesmerising music of his era.

A virtuoso guitarist with a laid-back but highly expressive voice, he made innovative records that defied categorisation and thrillingly blurred the boundaries between folk, jazz, blues and rock. At his height, every note he played or sang seemed to be imbued with a spacious elegance and sublime airiness all too rare in the hurly-burly of modern popular music.

Although he never attained huge commercial success, he was regarded by his contemporaries as a unique and inimitable talent. Among his collaborators were Eric Clapton, Steve Winwood, Dave Gilmour and Phil Collins, while successive generations of younger musicians have since referenced his work — particularly such peerless 1970s albums as Bless the Weather, Solid Air and One World.

In truth, by the mid-1980s his best work was all behind him. He was beset by personal problems and debilitating bouts of alcoholism that took their toll on his health, and his later recordings lacked the timeless mastery and magic of his early work.

He became infamous for his erratic live performances, falling off the stage on more than one occasion. Yet such was the enduring power of his early recordings that his fans seemed prepared to indulge and forgive him.

Iain David McGeachy was born in New Malden, Surrey, in 1948 to parents who were opera singers. He spent much of his childhood with a grandmother in Glasgow, where he attended Shawlands Academy.

By his mid-teens he was playing guitar in Scottish folk clubs, where he was helped considerably by the patronage of the singer and guitarist Hamish Imlach. By the time he was 18, he was playing professionally on the London folk club circuit and in 1967 he became the first signing in Chris Blackwell’s expansion of Island Records to become a fully independent label.

His debut album, London Conversation, appeared in 1968 and was a relatively restrained recitation of the solo acoustic set that he was performing in folk clubs at the time. By the end of the same year, however, it had been followed by The Tumbler, a far more adventurous recording that included the jazzy tones of Harold McNair’s flute and signposted what was to come.

Martyn’s unique style was developed further on his next two albums, Stormbringer and Road to Ruin, both of which appeared in 1970 and were credited jointly to Martyn and his wife, Beverley Kutner.

Recorded in Woodstock in upstate New York and brilliantly produced by the folk-rock pioneer Joe Boyd — whose other acts included Fairport Convention and Nick Drake — Stormbringer featured a host of top US session men, including the Band’s drummer, Levon Helm, and boasted a more expansive rock sound.

Road to Ruin pushed the folk-rock envelope even further and marked the first appearance of Martyn’s longest-lasting collaborator, the double bass player Danny Thompson of Pentangle.

When neither album sold particularly well, Island — just starting to taste big success with Cat Stevens — concluded that it would be easier to market Martyn as a solo singer-songwriter than as a duo, and Beverley was unceremoniously relegated to the background, making only occasional “guest” appearances as a backing singer while raising a family.