Peter, Paul & Mary have long mixed political and social activism into their music, and even after 55 years, Peter Yarrow and Noel Paul Stookey are still working to better the world.

The two singer-songwriters — Mary Travers passed away in 2009 — will be taking the stage at Symphony Space for “The Songs of Peter, Paul & Mary,” which plays double duty. It is a benefit for the anti-bullying organization Operation Respect, and a show to honor Robert De Cormier, the iconic folk group’s longtime musical director.

Operation Respect, founded by Yarrow, works to help foster safe, bully-free spaces in schools and other organizations that are geared toward children through the use of music, curriculum and training.

“My mother was a schoolteacher and I’ve always believed that education is the way to really transform from the grassroots up,” Yarrow, 78, says. “Now we face a circumstance where bullying has become a sport, where you go to TV and you look at the reality shows and it’s a constant and prevalent. You see it in the presidential election, you see it in Congress and you see that there is a skewing of the value system in the United States. That’s very, very painful, and so the work that we started to do was prescient.”

A historic group

Peter, Paul & Mary, which started in New York City in 1961, is famous for beautiful harmonies and well-known renditions of songs such as “Blowin’ in the Wind,” “Don’t Think Twice, It’s All Right” and “Where Have All the Flowers Gone?,” as well as the perennial children’s favorite “Puff (The Magic Dragon).” They also made headlines for their social contributions and influence — the group performed at the 1963 March on Washington where Rev. Martin Luther King Jr. delivered his “I Have a Dream” speech. Stookey says has that sense of activism has flowed through to new generations.

“I think to a certain extent, the younger generation have discovered the music, that is to say, that much like people in the ’60s did, that music can have an import in their lives, and not just be for dancing,” Stookey, 78, says. “I think all of us need to dance at some point in our lives, but ... there comes a time when you have to take responsibility and you want to add something to the world around you. ... They carry with them the premise and the understanding that music is a great equator. It provides a connection to the heart of everyone and goodness knows what we need in this contentious times is a sense of compassion.”

Honoring a friend

Besides being a benefit, the concert will also pay tribute to De Cormier, 94, who started working with the group in 1978 as their musical director.

“You’ve heard of the fifth Beatle, George Martin,” Yarrow says. “[De Cormier] was the fourth member of our trio in terms of creating the arrangements for the songs.”

In addition to the two folk legends, the show will feature singers from the New York Choral Society, which De Cormier had been the musical director and conductor of, and a chamber ensemble from Yarrow’s alma mater, Fiorello H. LaGuardia High School of Music & Art and Performing Arts.

“This is a concert to celebrate Robert De Cormier and his extraordinary achievements that he has given to music, to Peter, Paul & Mary, and the world of music that appreciates that kind of heart that he brings to it,” Yarrow says.

While the singers sung the praises of De Cormier’s orchestration skills, Stookey pointed out one particular song where he was particularly impressed by his work.

“De Cormier is amazing insofar as he treats each of the stories of folk music as a motion picture, and he writes a background score,” Stookey says. “‘Puff (The Magic Dragon)’ is not generally thought of as a heavyweight song. However, there is a section in the second verse where he says, ‘Together they would travel on a boat with billowed sails,’ and De Cormier wrote the greatest, wettest wave you’ve ever felt in your life underneath those words, and the orchestra does this beautiful swell.

“I’m usually singing that part of the verse,” he continues, “and I stay out of the way because I want the audience to get wet.”

Yarrow adds, “It was as if you could just feel the wind filling the sails. It’s just amazing. He paints pictures.”