For the past three decades and counting, Amy Ray and Emily Saliers have been carving out a unique place in contemporary acoustic-pop music. Best known as Indigo Girls, the Grammy-winning duo from Georgia share a love of vocal harmonies, strong songwriting skills, and a keen interest in social causes. The musical pair, who both came out as lesbians just after the start of their success and have separate family lives, have sold over 14 million records to date and are the only duo with Top 40 titles on the Billboard 200 from the 1980s through the 2010s. Their 15th studio album “Long Look” arrives this spring. As the two discussed recently, it’s the space they keep between themselves that holds Indigo Girls together.

Mike Horyczun: When you started out, did you think Indigo Girls would have the kind of staying power that would last into the 2020s?

Emily Saliers: All we knew was that this was the most fun thing ever that we landed on, just learning songs together and knowing that we wanted to incorporate original songs into our repertoire. There was no thought of a long-term future. There was just a thought of ‘What’s the next best gig?’ And the gigs just kept coming and they still keep coming.

Amy Ray: I was really excited when Emily and I started singing together. We were in high school, and even if we didn’t do it for a living, even if we never went anywhere, just the feeling of being in harmony with someone when it’s working really well is incredible. We knew at the time that we had a really great community around us, too. And it was really important for us to always have a community around us and preserve some of the old relationships as we went on. If you want longevity, it’s an ecosystem. You’ve got to nurture it.

MH: Looking back, would you have done anything differently in your career?

ES: That’s a good question, because I feel like overall, we never compromised. I think if anything, for me personally, I wish I hadn’t had any fear at all about coming out. And even though we came out pretty early, like 1991 or so, I suppose I wish I’d had the courage earlier. But I also believe that things happen when the time is right for it to happen. We didn’t make any mistakes, and we didn’t make any compromises at all. So I don’t think I would change anything

AR: The women’s community is so important to us now and is so much of our audience, but at the time we were scared. It was a political aspect of feminism, around separatism, and we didn’t really understand it. We didn’t really know a lot about the queer culture. I was too scared and fearful to open my mind to being politicized that early on. That’s just a personal regret. We didn’t have that many options all the time. It wasn’t like there were that many roads we could go down, and we chose the wrong one. We just went down the road that was there, because we had to build the road ourselves.

MH: It’s so rare to have a musical duo with such a long history. What is the magic that keeps you two together?

AR: We give each other a lot of space. And I think we have very different lives. I live an hour and a half from Emily in the middle of the woods. She lives in the city. And that really defines us in a lot of ways. We’re very opposite about a lot of things, but our moral compass is really similar. We might take different approaches to things, but it’s good, because we have a lot of faith in the process, and we have a belief that what we do together is going to be more magic than anything we can do by ourselves.

ES: Amy mentioned space, and it’s so true. We don’t write our songs together. And that’s critical, because we have our own way of expressing ourselves that’s very different from the other. Amy’s got a little bit more of a rock and roll sensibility. And I’ve got a little bit more of a lyrical sensibility in terms of stream of consciousness or whatever it is. I think at the heart of our relationship is a deep found respect and love for each other. Despite the fact that we’re very, very different personalities like Yin and Yang. I think the key is that sense of difference, the sense of autonomy, and the sense of respect.