great barrington, mass. | Peter Yarrow had been at Eisner Camp barely an hour before he began strumming the melody to “Puff the Magic Dragon” on his guitar. Campers here in the heart of the Berkshire Mountains aren’t old enough to recognize him, but they know his music, particularly the classic song about the mighty dragon and his departed playmate Jackie Paper.

As he played, Yarrow began riffing on the ideas of mutual respect and personal responsibility, using for inspiration the “Puff” lyrics that have often been construed — falsely, the composer insists — as a coded reference to marijuana use.

At what point in our life, he asked, do we start to stand up and take responsibility. A boy stood up to suggest, tentatively, at the age of bar and bat mitzvah.

“That’s right,” Yarrow said. “When people ask me what ‘Puff the Magic Dragon’ is about, I say it’s about being bar/bat mitzvah. Is that the case? No, but it’s a good story.”

Yarrow has lots of good stories to tell after nearly 50 years of performing, the bulk of them as part of the legendary folk trio Peter, Paul and Mary. The group played at the March on Washington in 1963, and their music became part of the soundtrack to the social struggles of that decade.

At 69, Yarrow is still fixed on issues of social justice.

Though in high school he was a member of the Socialist-Zionist youth movement Hashomer Hatzair, Yarrow has never been closely associated with Jewish causes. In his meetings with campers at Eisner, however, he went out of his way to couch his account of ’60s activism in the vernacular of tikkun olam, the Jewish shorthand for social justice.

“There’s been a great sense that what is Jewish within us is not just about Jews, but it’s about all people who are suffering enslavement or deprivation of their rights,” Yarrow told the campers July 12. “When I sang at the March on Washington with Paul and Mary, right before Martin Luther King delivered his ‘I Have a Dream’ speech, it was all one thing. We, I, as a human being, as a Jew, as a person of consciousness, had to act Jewishly. And I more than others, like yourself, because in our history we have known slavery and we have known prejudice.”

Yarrow sings a little, talks a little, and generously gives hugs and kisses. His message is less spiritual than social and, in keeping with his tie-dyed roots, decidedly countercultural. He assailed society’s willingness to see ridicule and humiliation as the stuff of entertainment. When children internalize that, he said, the consequences can be disastrous.

Yarrow has had to overcome his own experience with humiliation, having been convicted of taking “immoral and improper liberties” with a 14-year-old girl who came to his hotel room after a concert in 1970. Yarrow served three months in prison. His public rehabilitation was helped along 11 years later with a pardon from President Carter, and these days he’s rebuilt his reputation to the point where he can shift his focus from writing songs for the masses to developing educational curricula for the young.

In 2000, Yarrow founded Operation Respect, a New York-based nonprofit that works to combat childhood bullying. And though he stresses the consonance of his focus on bullying with his life’s work of political activism through music, he concedes that he has basically given up on adults.

“It says it starts with bullying, it starts with pushing ridicule, making fun of someone, and it builds to racism, prejudice, hatred, war, Holocaust,” Yarrow told counselors-in-training, his voice dropping to a whisper. “If we want to interrupt the cycle, you are a critical force in this.”

It is a message that resonates at the Reform Eisner Camp, which has waged a seven-year battle against bullying. Eisner employs a full-time “inclusion coordinator” and requires campers to sign an anti-bullying pledge.

Campers use the curriculum developed by Operation Respect and know the words to its theme song, “Don’t Laugh At Me,” by heart.

After meeting with small groups of campers during his afternoon at Eisner, Yarrow capped the day by performing an hourlong set for the entire camp. But it was his performance of “Don’t Laugh At Me” that brought the 700 campers and counselors to their feet, swaying arm in arm and singing along.

“Thank you so much for standing,” Yarrow said. “That’s beautiful. You make me feel like I’m at a peace march.”