Folk artists Joan Baez, Mary Chapin Carpenter and Indigo Girls Amy Ray and Emily Saliers are longtime friends offstage. On stage they’ve joined forces in the collaboration Four Voices.

There’s a lot to be done in preparation for the tour. Besides negotiating the vast expanse of their combined catalogs when choosing a set list, there’s even figuring out the seating arrangements.

“We were just discussing what kind of chairs or stools we wanted,” Baez says with a laugh, calling on her way to a Four Voices rehearsal in Atlanta. “Chapin’s legs are short and one of mine has a weird knee. We allow ourselves five minutes for what we call ‘organ talk.’ After that we don’t get to complain about all the things that are going wrong with the female body at this age. Listen, I’ve got 20 years on them. I’m biting my tongue through the whole conversation.”

The four women bring sizable reputations to the stage. Baez is a folk legend and longtime political activist who became a star during the 1960s folk boom. She was friends with civil rights icon Martin Luther King Jr., performed at Woodstock and was instrumental in the early career of her one-time boyfriend Bob Dylan. This past April, she was inducted into the Rock and Roll Hall of Fame.

Although Baez is a well-known interpreter of other artists’ material, she’s written some fine songs of her own including her 1975 hit “Diamonds & Rust,” a bittersweet remembrance of her relationship with Dylan. Her most recent self-penned song is the viral hit “Nasty Man,” a scalding and humorous ode about President Donald Trump.

Carpenter has built a career as a trenchant singer-songwriter. In the 1990s, she became an unlikely mainstream country star with a string of hits including the feminist anthem “He Thinks He’ll Keep Her” and a cover of Lucinda Williams’ “Passionate Kisses.” Georgia natives Saliers and Ray formed the Grammy-winning folk-rock duo Indigo Girls in the 1980s and recorded hit singles “Closer to Fine” and “Galileo.”

We caught up recently with Baez to discuss the first time she performed in public and her thoughts on writing about Trump. This is an edited transcript.

Q: In your acceptance speech at the Rock and Roll Hall of Fame induction ceremony, you said “my public is a kind of family.” Can you expand on that?

A: Somebody was chiding me once that I really liked this business of people coming up to me. Yes, I do. Nobody ever comes up and says anything horrible, because people who don’t like me are basically chicken. (laughs) So people say really nice stuff. How can I complain about that? They feel like they know me, even though they don’t. I know I’ve been part of their lives and it’s important for them to say what they need to say. They’re good people.

Q: In your speech, you said your granddaughter didn’t really know you were famous until you took her backstage to meet Taylor Swift.

A: My granddaughter knew her abuela (grandmother) was famous, whatever “famous” means to a 12-year-old. She knew it meant a lot of special treatment for her family. But Taylor Swift was this monster thing in her life at that moment. She simply couldn’t believe that she was meeting Taylor. So now I have this sort of cool element that I didn’t have before. (laughs) My granddaughter really appreciated it and had a wonderful time. Taylor was wonderful to us.

Q: You’ve described your voice as “a gift.” How old were you when you began singing and how did you feel about your voice in the beginning?

A: I started singing and playing the ukulele around 13 and graduated to the guitar at 15. I thought I had a pretty voice but I didn’t think it was anything special until I was in my late teens. I was Mexican in Southern California and was having difficulty finding a niche for myself in school. At the age of 13 or 14, I sang at lunchtime for the quote popular girls. It wasn’t exactly having friends by a long shot, but it was something. I really enjoyed having an audience. But being able to play my ukulele and sing my rhythm and blues songs to myself at night kind of saved my young life.

Q: Your first gig in 1958 was at Club 47 in Cambridge, Massachusetts. What was it like to perform in public for the first time?

A: My mother, father and sister showed up and that was it. (laughs) I saw my boyfriend through the window, walking back and forth outside. I don’t know what he was contemplating at the time, but he finally came in and that made it an audience of four. The next week, the place was half full. The next time, it was all the way full. Then I played the Newport Folk Festival. When I came back, the lines were around the block. It happened very quickly.

Q: What is your main memory of that first Newport appearance in 1959?

A: People say “my knees were shaking.” Well, my knees actually were shaking. (laughs) I was hanging onto the handrail to get up to the stage. I was so nervous. I’d never seen that many people all in the same place. But I managed to get across the stage. We launched our song and I got a huge response. I was pleased with that. I liked it and knew I wanted to do more of that.

Q: You’ve covered so many great songs and written some yourself. What was the breakthrough for you as a songwriter?

A: I was 10 years in and still doing (cover material). Somebody asked me, “Do you write songs?” I said, “No.” They said, “Why don’t you try?” “Sweet Sir Galahad” was the first one that came out. Exactly how I consider my own songwriting is that I’ve written one really really stupendous song — “Diamonds & Rust” — and all the rest are either good or mediocre. (laughs) Between 25 and 30 years ago, the songs stopped coming. That’s the best way to say it. They just didn’t arrive anymore. So I quit trying. The only thing I’ve written since then is “Nasty Man.”

Q: When you wrote “Diamonds & Rust,” did it come quickly to you?

A: It started off as another song. Then the words started to morph. When you write a song that deep, the words come from some place else. But when the songs stop coming, it would be so contrived to try and force it. Since then I’ve just been doing other people’s music. Sometimes they write it for me. Sometimes I search for material that matches the mood of an album. Right now I’m working on a record that is nearly finished. It’s the first time I’ve been in the studio in eight years. There’s nothing of my own on the album but that doesn’t really matter. I’m really thrilled with the record. It’ll come out in the spring of 2018.

Q: Where were you when you wrote “Nasty Man?”

A. I was in my kitchen. It took a couple of days. There were so many verses, I just had to pick the best ones. (laughs) They just kept coming because the situation is so awful and there are so many images of its awfulness. This isn’t a laughing matter, but you have to laugh anyway. The song, itself, becomes something of a laughing matter because we’d go crazy if we didn’t keep laughing.

If you go

The closest that the Four Voices tour will get to southeastern Connecticut is Tanglewood in Lenox, Mass., for a 7 p.m. concert this Saturday. Tickets are $25-$99 for the 7 p.m. show. Visit tanglewood.org.