American folk music has spanned the entire history of the United States. With roots that go back to Europe and Africa, folk music derives much of its style and techniques from English ballads, hymns, Irish and Scottish traditional music (especially fiddle music) and African-American blues.

While traditionalists in the early 20th century continued to perform the songs and styles that had been passed down orally, such as Appalachian and Cajun music, the times were a-changing.

The so-called American folk-music revival began during the 1940s, and peaked in popularity in the mid-1960s with the advent of singer-songwriters who wrote their own material. The revival was driven by lyrics infused with social and political messages sung by the likes of Bob Dylan, Pete Seeger and Joan Baez, as well as groups such as the Kingston Trio, the Weavers and the Byrds.

In celebration of that era of folk-music greats, the State Theatre Center for the Arts, Easton, presents “Lonesome Traveler,” a concert version of the acclaimed Off-Broadway musical, 8 p.m. Feb. 3.

A cast of charismatic young singers and instrumentalists is joined by folk music legend Peter Yarrow of Peter, Paul and Mary.

The concert showcases many of the songs of social comment and protest that marked the period, such as “The Times They are a Changing,” “This Land is Your Land,” and “Turn, Turn Turn.”

Yarrow has high praise for the concert and its performers: “The show is so thrilling. I can’t remember when I’ve been so moved and so excited about doing a concert.”

After seeing the play in New York City, Yarrow went on stage and sang a song with the cast.

“I wrote a letter telling them how wonderful they were, and how grateful I was, and they invited me to go with them as their special guest. It was a delightful surprise to me,” Yarrow says in a phone interview.

The Grammy-award-wining Peter, Paul and Mary trio was one of the torchbearers of social commentary music in the ‘60s, with mega-hits “Where Have All the Flowers Gone,” “If I Had a Hammer,” “Leavin’ on a Jet Plane,” and “Blowin’ in the Wind.” It is no surprise, then, that Yarrow still speaks out about social and political issues.

Even though the ‘60s was a turbulent time of the Civil Rights movement, Cold War anxieties, the aftermath of the Korean War and the United State’s unpopular involvement in Vietnam, Yarrow says, “There was so much spirit we all shared in those days. Our creativity was sparked by a sense that times were changing for the better. We had an assurance of that.”

Yarrow is not as optimistic today. “We don’t have that feeling in the country today. The times have changed terribly. There is a fear that we will lose the heart and soul of what America is about to a lot of us.”

Citing the divisiveness among Americans, he continues, “We can disagree. That is the nature of democratic discourse, but people who disagree should not despise each other.”

To that end, Yarrow is co-producing a documentary for Better Angels, a non-profit organization that brings groups of voters on both sides together to try and eliminate their biases about people with opposing political views.

Asked if folk music is still relevant, Yarrow answers, “Absolutely! It has even greater relevance in some cases because of the urgency.”

He says the “Lonesome Traveler” audience “will come away feeling they’ve been given a psychological break from the vitriol. They will feel a sense of unanimity and hopefulness. They will feel they have that capacity to reach out again the way we did in the ‘60s to be part of resolving problems.”

Yarrow is still touring across the country. His motivation? “When I perform I experience a sense of community that fills me with energy, hope and empowerment.”

Yarrow has been called an icon, a musical legend and an activist, but he says he wants to be remembered “as one of the people, one who followed the wonderful path forged by Pete Seeger and the Weavers and others in which music became a way of mobilizing community and bringing people’s hearts together in ways to make the world a better place.”

Tickets: State Theatre Center for the Arts box office, 453 Northampton St., Easton; statetheatre.org; 1-800-999-7828; 610-252-3132