Reynolds (right) with Bob Shane (c) and Dave Guard
Nick Reynolds, a founding member of the Kingston Trio - who spearheaded the US folk music revival of the late 1950s, has died in San Diego at the age of 75.
The musician had been in hospital with acute respiratory disease. He died on Wednesday after his family took him off life support, son Joshua Reynolds said.
The Kingston Trio's cover of the folk song Tom Dooley was a chart hit in 1958, and launched the band's career.
The Trio paved the way for artists such as Bob Dylan and Joan Baez.
"Dad was so happy he turned people onto music in a way that people could really approach it, in a simple and honest way," Josh Reynolds told The Associated Press.
"He was a very gracious and loving performer."
Born on 27 July 1933 in San Diego, the musician was taught to play the guitar by his father, a navy captain.
He began performing as a young boy, singing with his father and two sisters.
He met Bob Shane soon after leaving college, and it was Shane who introduced him to Stanford student Dave Guard - with the three of them later forming the Kingston Trio.
Their debut hit, Tom Dooley, earned them the best country and western performance at the inaugural Grammys in 1959.
The group went on to win a Grammy in the following year for best folk performance, with their album The Kingston Trio At Large.
Guard left the trio in 1961 following a dispute, and was replaced by John Stewart - who died earlier this year. Guard died in 1991.
However, despite a popular hits such as Reverend Mr Black, by the mid-60s they were overshadowed by the likes of The Beatles.
After leaving the group in 1967, Reynolds moved to Oregon to concentrate on raising his family.
In the mid-1980s, he moved back to California where he recorded an album with Stewart.
He was later reunited with Shane and remained with the group until his retirement.
A "devoted family man," Reynolds is survived by his wife, two sons and two daughters.