Dave Guard, founder of the Kingston Trio, which brought folk music from the coffee houses to mainstream America with songs such as the haunting "Tom Dooley" and the rollicking "MTA," has died at 56.

His daughter, Sally Guard of New York, said Saturday that her father died Friday at home in Rollinsford of lymphoma."I'm very upset," said Nick Reynolds, a member of the trio since its founding in 1957. Reached by telephone in Coronado, Calif., Reynolds said he had visited Guard "two months ago and he was in remission."

"We were talking about doing a reunion," he said. "We were going to have John Stewart (who replaced Guard) and George Grove (the newest member) and the rest of us sing in different combinations, a kind of retrospective."

The period of the original Kingston Trio, between 1957 and 1961, when Guard left the group, "was the highlight of our careers," said Reynolds, who with Bob Shane, a high school friend of Guard in Hawaii, has remained with the group.

Guard graduated from Stanford University with an economics degree in 1956. Around that time, Reynolds recalled, he and Shane were attending Menlo College, in Palo Alto, Calif., and they used to get together to sing for fun.

"We then started singing for beers," Reynolds recalled. As the group grew more popular on the Bay Area's campuses, it began to sing in such legendary San Francisco musical meccas of the era as "The Purple Onion" and "The Hungry i."

"That's when our career took off," Reynolds said.

In 1959, before the folk category was established, the group won a Grammy for the best country and western recording for "Tom Dooley," the group's best-selling single.

By 1960, the group won the first Grammy for the best folk album.

The original trio had nine gold albums, "The Kingston Trio at the Hungry i," its most succesful.

Among the group's hits were "The MTA," "Where Have All the Flowers Gone?" and "Scotch and Soda," the latter featuring Reynolds.

Guard was the tallest member of the group, usually playing banjo, and was considered the trio's intellectual, Reynolds said. "Bobby was considered the sex symbol and I was the short, little guy," Reynolds said.

After leaving the group, Guard started the Whiskyhill Singers and moved to Australia, where he lived until 1968 and where he was host of a television show. Guard also wrote several books, including a manual on guitar technique as well as books of fairy tales.

Guard is survived by his mother and three children.