CONCORD, N.H. -- Dave Guard, 56, a founder of the immensely popular 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," died of lymphoma March 22 at his home in Rollinsford, N.H.

In 1957, he, Bob Shane and Nick Reynolds founded the trio. Mr. Guard stayed with the group until 1961, when he left and was replaced by John Stewart.

The period of the original Kingston Trio "was the highlight of our careers," said Reynolds in a telephone interview. Reynolds and Shane, a high school friend of Mr. Guard's in Hawaii, has remained with the group. The trio's newest member is George Grove.

Mr. Guard, a native of Honolulu, 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 San Francisco 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 Award 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, with "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."

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

Survivors include his mother and three children.