Before a scruffy-looking young man called Bob Dylan and the pure-voiced Joan Baez were crowned its king and queen, the biggest stars of the US folk music revival were the Kingston Trio. Nick Reynolds sang the middle part of the trio’s clean-cut triple harmonies and added polite percussion to their hit versions of songs such as Tom Dooley and Where Have All the Flowers Gone.

The trio’s success was built around a reassuring wholesomeness, the appeal of which faded swiftly once the folk revival that they had helped to launch took off in new and more challenging directions. Yet Dylan himself — whose songwriting genius in effect rendered the trio redundant — was gracious enough to pay tribute to their influence on him in the late 1950s, before he found his ultimate role model in Woody Guthrie.

“The first thing that turned me on to folk singing was Odetta,” he once said. “From Odetta, I went to Harry Belafonte, then the Kingston Trio, little by little uncovering more as I went along.”

Reynolds was born in 1933 in San Diego and was taught to play the guitar and ukulele as a boy by his father, a captain in the US Navy. He formed the Kingston Trio in San Francisco with fellow students Bob Shane and Dave Guard in 1957, and the following year their recording of Tom Dooley topped the US charts. The song also made the Top Five in Britain, where the skiffle craze was in full swing.

Tom Dooley won the Kingston Trio an award at the inaugural Grammy ceremony but it was a mark of how little regard there was for folk music at the time that in that first year there was no designated folk category. The trio won for “best country and western performance”. Their chart success — and the reception that groups like the Kingston Trio were getting on college campuses all over America — swiftly changed that, and by 1959 a folk category had been initiated. The Kingston Trio won it, of course, with their debut album The Kingston Trio at Large, which spent 15 weeks at the top of the Billboard charts. Reynolds and the trio had further hits with Tijuana Jail, M. T. A. and a version of Pete Seeger’s Where Have All the Flowers Gone, but by the time Guard left in 1961 to be replaced by John Stewart (obituary, Jan 22), the trio had already peaked as an increasingly radical folk audience rejected their non-threatening, apolitical stance. In their striped, button-down shirts and with a clean-cut image reinforced by their choice of middle-of-the-road material, they lacked the radicalism of Woody Guthrie and the Weavers (who had been blacklisted during the McCarthyite era) and the sexuality of rock’n’roll. Their “safeness” was further epitomised when in 1964 the trio were invited to sing Where Have All the Flowers Gone on the White House lawn for President Johnson — a better career move might have been to join a civil rights march in Alabama.

In an interview in 2006 Reynolds described the dilemma they had faced and admitted that they were ultimately swayed by commercial considerations. “We had to sit down and make a decision: are we going to remain apolitical with our music or are we going to slit our throats and get blacklisted for doing protest music?” he said. “We decided we’d like to stay in this business for a while. And we got criticised a lot for that.” In 1967 the trio accepted that they had become an anachronism and broke up.

Reynolds moved to Oregon where he brought up his family, took up sheep farming and ran a theatre. He returned to music in 1983 when he moved back to California, reuniting with Stewart — by far the most successful former member of the group as a solo artist — on the album Revenge of the Budgie.

In 1991 Reynolds teamed up again with Shane in a reconstituted Kingston Trio and sang with them until 2003. In recent years, he and Stewart ran a “Trio Fantasy Camp” in Arizona, where they taught a new generation of folk performers — and some older ones who simply wanted to recall their youth — to play and sing the trio’s hits and folk standards.

He is survived by his wife, Leslie, and four children.

Nick Reynolds, folk singer, was born on July 27, 1933. He died of acute respiratory disease on October 1, 2008, aged 75