John Herald, a guitarist and singer whose group the Greenbriar Boys was among the first bluegrass bands in New York in the 1960's, died on Monday at his home in West Hurley, N.Y. He was 65.

The Ulster County medical examiner has not ruled on the cause of death, but the state police said it appeared to be suicide. Mr. Herald's body was found on Tuesday.

A regular presence on the folk and bluegrass scene for more than four decades, Mr. Herald was known for his accomplished guitar picking and his strong and boyishly nasal voice, which grew gentle in later years. A noted songwriter, his songs were performed by Linda Ronstadt, Maria Muldaur, Joan Baez, and Peter, Paul and Mary.

The Greenbriar Boys, formed by Mr. Herald with Eric Weissberg and Bob Yellin in the late 1950's, were active on the New York folk scene. In a review in 1961, Robert Shelton of The New York Times praised a young Bob Dylan at Folk City in Greenwich Village; the headlining act that night was the Greenbriar Boys.

The band "whips up some of the fastest, most tempestuous bluegrass music this side of Nashville," he wrote of the concert. "They join Mr. Herald, a leather-lunged tenor whose athletic, high-range country yodeling is a thing of wonder."

The Greenbriar Boys became the first "Yankee" band to win the Galax Fiddlers Convention in Virginia. The group recorded for Vanguard and Elektra and underwent various personnel shifts until disbanding in the late 60's.

Born in Manhattan, Mr. Herald grew up in Greenwich Village, the son of Leon Serabian Herald, an Armenian immigrant who was a published poet. He was inspired to play music when he was at summer camp and saw Pete Seeger perform.

Mr. Herald performed solo and with the John Herald Band through the 70's. He also performed with the Woodstock Mountain Revue. He recorded an album, "Roll On John," released in 2000, and was working on a new CD at the time of his death.

His marriage to Kim Chalmers ended in divorce. No other immediate survivors are known.