“They recorded all kinds of things,” Mr. Rapp said of Impact Sound, “so there were lots of different instruments at the studio — Middle Eastern groups and everything — so any kind of instrument in the world seemed to be right there, and we were allowed to use them. A lot of it was just impromptu.”
A second album, “Balaklava,” came in 1968, and others followed, Mr. Rapp being the constant in an ever-changing band lineup, writing the songs, singing and playing assorted instruments.
“The Florida-born Swine are not easy to describe,” Paul Nelson wrote in The New York Times in 1968. “Like Country Joe and the Fish, a well-known Berkeley band, they are either so simple they are complex or so complex they are simple.”
The group switched to the Reprise label after two records, and Mr. Rapp eventually went solo, on albums like “Sunforest” (1973). But he then changed course radically, leaving music, enrolling in college and in the early 1980s receiving a degree from the University of Pennsylvania Law School.
“I wanted to do something more real, with a more direct effect on people,” he told Knight-Ridder Newspapers in 1987, by which time he was working for a Philadelphia law firm, handling cases involving matters like workplace discrimination.
But he returned to performing in 1997, and he continued to make occasional appearances after that. In 1999 he released a new solo album, “A Journal of the Plague Year.”
“I got into a 12-step program for reclusivity,” he explained to an audience at the Knitting Factory in Manhattan in 1997. “This is my 12th step.”
Thomas Dale Rapp was born on March 8, 1947, in Bottineau, N.D. His parents, Dale and Eileen, were both teachers.
He grew up in North Dakota, Minnesota and Florida, where he graduated from Eau Gallie High School, just north of Melbourne, in 1965.
The songs he wrote for Pearls Before Swine might be antiwar, like “Uncle John” from the first album, released in the midst of the Vietnam War:
With your chamber-of-commerce soul
You talk of war so bold
God is on our side, but
He’s lost in your wallet fold.
Or they could be airy, or humorous, or mysterious. “Space folkies,” one writer called the band, and its sound was variously described as “acid folk,” “hippie folk” and “psychedelic rock.” Mr. Rapp had his own description.
“I like to write about the old things — old myths and legends, Valhalla, elves and dwarfs, magic rings and magic men,” he told The New York Times in 1968. “If you really want to give our particular sound a name, how about ‘transcendental rock’?”
Among Mr. Rapp’s claims to fame is “Rocket Man,” a song from Pearls Before Swine’s 1970 album, “The Use of Ashes.” It is said to have been among the inspirations for the Elton John hit of the same name.
Pearls Before Swine sold a decent number of records for a non-Top 40 group, but Mr. Rapp said he never made any money off the band, for various reasons, including being mishandled by a shady producer. He told The Washington Post that in 1976, figuring any future songwriting and performing would just enrich other people, he quit the music business and got a job in Cambridge, Mass., selling popcorn at a theater.
“I knew at the end of the week, every single week, I would get $85,” he said. “I was insane with joy.”
He eventually enrolled at Brandeis University, graduating in the late 1970s, and then law school.
“I think of myself as doing ’60s law,” he said in the 1987 interview. “The major body of law I do is discrimination. Most of the major statutes in my field come out of the 1960s.”
But thanks to the internet and some album reissues, new fans continued to find his music, and in 1997 he was invited to appear at the Terrastock Festival in Providence, R.I. It was the start of a mini-resurgence. Last year saw a 50th-anniversary reissue of “One Nation Underground.”
Mr. Rapp’s first marriage, to Elisabeth Joosten in 1968, ended in divorce in the mid-1970s. His second marriage, to Susan Hein, also ended in divorce. In addition to his son, he is survived by his wife, Lynn Madison, whom he married in 1995; two sisters, Kathy Parks and Patty Lent; and a granddaughter.
Mr. Rapp once told the story of being on the bill at a Philadelphia concert sandwiched between two other acts. He was told that because of a scheduling blunder he would have only one minute to play. The promoter said he could collect his pay and simply leave, but Mr. Rapp claimed his 60 seconds.
“I said, ‘I can do a one-minute show, and I can get a standing ovation,’ ” he recalled in the 1987 interview. He took the stage and played nothing, instead simply saying, “Would you please stand up and applaud if you think he’s guilty?”
It was 1974, when President Richard M. Nixon was embroiled in the Watergate investigation.