When Bob Dylan shocked the audience at the 1965 Newport Folk Festival by going on stage with members of the Paul Butterfield Blues Band to play electric for the first time, only one person outside Dylan's inner conclave knew what he was planning  the photographer David Gahr.

The site was systematically cleared beforehand to allow Dylan and the band to do their soundcheck for the controversial, ground-breaking set, butnobody dared ask Gahr to leave. Hewas a fixture at all the major folkmusic events of the period and came to be even more revered than most of those he pictured, his iconic shots effectively documenting the story of American folk music from the 1960s onwards.

Irreverent and irascible, the cigar-smoking Gahr was sharply disdainful of anyone who tried to control his output or limit his access, but with his bawdy humour, engaging personality and sharp eye for detail, he had instant empathy with most musicians. He maintained a warm relationship with Dylan for over four decades, shooting the cover of his 2001 album Love and Theft  his last serious photo shoot  and his credits appear on dozens of other memorable LP covers.

His 1970 shot of Miles Davis, back arched and face clenched in concentration, aggressively playing the trumpet on the cover of A Tribute to Jack Johnson is an enduring classic; equally telling is his portrait of a contemplative, troubled-looking Bruce Springsteen on the cover of his 1973 album The Wild, The Innocent & The E Street Shuffle.

Working for Rolling Stone magazine, Time-Life (for whom he completed over 2,000 assignments), CBS Records and others, he won the confidence and admiration of many supposedly difficult subjects, producing iconic images of greats like John Lennon, Johnny Cash, Van Morrison, Willie Nelson, Joni Mitchell, Laura Nyro and, a particular favourite, Janis Joplin. One of his most celebrated pictures was a rare shot of Joplin laughing, which appeared on the cover of Rolling Stone in 1970, while another of his Joplin images was selected by Time magazine to represent a retrospective look back on 1968, 20 years after the event. "You know you're a star when you're photographed by Gahr," the folk singer Carolyn Hester commented.

David Gahr was born in Milwaukee, the son of Russian immigrants and one of five children growing up in a largely black area, where he developed a deep love of blues music. He was a talented student, studying at the University of Wisconsin in Madison, where he earned bachelor's and master's degrees in economics. During the Second World War he saw action in Europe in the infantry, and after the war he studied for a PhD in political science at Columbia University in New York. He didn't complete his thesis, however, leaving to get married and raise a family. To earn money, he took a job at a Sam Goody record store in New York. This brought him into contact with various passing musicians in search of records and his life suddenly took a different turn.

Always a convivial character, he offered to photograph the musicians he met and just as the American folk boom of the early 1960s began to take shape, he found his vocation. He became part of the furniture on the folk scene, his omnipresent camera recording many historic moments on stage, although he was equally famous for capturing candid offstage shots. He also had a special knack with posed shots, mostly using natural light to create an intimate image of his subjects, who he kept on their toes with his high-energy personality peppered by affectionate insults, occasional vulgarities and a characteristically colourful running commentary on the state of the universe.

Blues giants like Mississippi John Hurt and Sonny Terry and Brownie McGhee, country heroes like BillMonroe and members of the Carter Family, jazz legends Charles Mingus and Miles Davis and most stars of the folk world, from Pete Seeger to Joan Baez, came into his orbit. An anthology of his work, The Face of Folk Music, featuring 500 of his shots plus essays by Robert Shelton, was published in 1968 and, long out of print, is now a collectors' item.

His work was not confined to music. He also photographed Andy Warhol and various writers, including Arthur Miller. At a surprise party to celebrate his 84th birthday, Gahr  who, despite ill health, retained his outrageous sense of humour  told the story of going to Miller's house one day to photograph him. He was met at the door by Miller's then wife, Marilyn Monroe, wearing only a bathrobe. She invited him in, opened her bathrobe and pulled out a photograph Gahr had previously taken of Miller. "It's my favourite photograph of all time," she smiled.

David Gahr, photographer: born Milwaukee, Wisconsin 18 September 1922; married (one son, one daughter); died New York 25 May 2008.