7 p.m. Friday, Tri-Lakes Center for the Arts, 305 Colorado Highway 105, Palmer Lake, $30-$40, $50 includes meet and greet; 481-0475, trilakesarts.org. SOLD OUT.

The Vietnam War changed everything, including music. At least that’s what Peter Yarrow, of the famous folk singing trio Peter, Paul and Mary, believes.

Mary Travers died of cancer in 2009, but Yarrow and Paul Stookey continue to perform, occasionally together. Yarrow will play at the Tri-Lakes Center for the Arts on Friday.

“It broke the country into two and that still exists,” he says from Lyons, where he performed at the Rocky Mountain Folks Festival earlier this month. “We have a big problem of our times and it’s a huge black hole of empathy. There’s so much greed and mean-spiritedness, and bullying is a sport. Those kinds of ways of being, the culture of that perspective, is so damaging to the spirit of America.”

It spurs the 77-year-old to continue doing what he’s always done – use music to bring awareness to social and political issues. Much of his show is devoted to playing the repertoire of Peter, Paul and Mary, but he intersperses the music with history and stories.

“I tell them how the song is meaningful to now,” he says, “how songs deal with current movements, like black lives matter, anti-fracking, the pipeline, Scott Walker, Occupy Wall Street. A lot of what I want to do is share that (even though) the music is not at the top of the charts it still has great meaning and currency.”

Yarrow reflects on the changes he’s seen in the decades since the trio rose to popularity with songs like “Blowin’ in the Wind,” “Puff, the Magic Dragon” and “If I Had a Hammer (The Hammer Song).”

“Music bound people together in a common purpose in the ’60s and some of the ’70s,” Yarrow says. “That is the reason you don’t see the kind of gathering together of spirits that was so characteristic of that era. That music itself was not just a reflection of those feelings but it was an active part of advancing the efforts by connecting people’s hearts and giving them the courage they needed and the sense they were not alone and the opportunity to validate what was motivating them.”

After the war, he says, music went from being about authentic expression to something else entirely.

“There are an extraordinary number of singer- songwriters involved in political efforts,” he says, “but because music has become so commercialized and modified, it is, to a large degree, all about making money. When money is the intervening variable and that becomes the determining factor whether it will be shared, what you get is mediocrity or worse most of the time. It’s a huge loss.”

JENNIFER MULSON, THE GAZETTE, 636-0270, JEN.MULSON@GAZETTE.COM