Lindsey Buckingham and Christine McVie sit across from each other on a Sony Pictures soundstage where they are rehearsing for their upcoming joint tour. McVie officially rejoined Fleetwood Mac in January 2014, but when it came time to hitting the road with Buckingham, he had but one requirement: “I told her you can’t leave [Fleetwood Mac] again,” Buckingham quips.

“I won’t, I won’t,” McVie playfully banters back.

When McVie left one of the most successful bands in rock history back in 1998, she says she firmly believed her music career was behind her. Instead, she felt herself rejuvenated after what she calls, “A hell of a retirement.” For his part, Buckingham, who has continued to explore his sound as a solo artist, also appreciated stepping away from the “big machine.”

But that big machine will make a big return this summer when the Mac and the Eagles co-headline the Classic West concert in Los Angeles the weekend of July 15 and Classic East two weekends later in New York. Buckingham also says the band will continue to tour in summer of next year. But otherwise, 2017 is about the debut of “Lindsey Buckingham/Christine McVie,” the pair’s first album as a duo. In support of the stellar album, the duo will hit the road June 21 in Atlanta for a trek that takes them through August 11, when it wraps in Bethlehem, Pennsylvania.

Variety spoke with the two about the new music, rediscovering their musical connection, and their collective amazement at a 40-year career that includes the tumultuous making of Fleetwood Mac classic, “Rumours.”

Take us through the early recording process of this album.
Lindsey Buckingham:
John [McVie] and Mick [Fleetwood] were in town and we thought, “Well, this will be like old-home week.” We went back to the Village [recording studio], where we did most of “Tusk,” and we didn’t necessarily concern ourselves with what it was. We just wanted to pursue the process again and tap into that side of ourselves. I think it took less than a week for us to be like, “Oh my god, this feels like a really strong symbiotic thing between the two of us.” It felt like a duet album almost immediately.

These days, duets have given way to “features.” Was there a template or inspiration for the idea of a joint album?
Christine McVie:
Classic duets? The Everly Brothers, Buckingham/Nicks… (Laughs)
Buckingham: That’s funny. Part of what’s cool about this album is it isn’t, “Oh, listen to those two parts, it’s Paul and John.” Her songs are her songs, and my songs are my songs. There’s more of a common center, but there’s still that sense of individualism.

Both of you have evolved and changed as songwriters and grown as musicians. How have you seen that growth in each other?
If you look at the whole time I was in the band, I only did, like, three solo albums — two really. “Out Of The Cradle,” I had already left because we’d done “Tango In The Night” and it was sort of the logical extension of crazy in terms of everyone getting ready to hit the wall with their habits. It was a difficult album to get through. And I didn’t want to take that on the road. So I was able to really concentrate on my solo work. It’s a small scale thing compared to Fleetwood Mac and what Fleetwood Mac entails on a political level, and what it may entail in terms of expectation on a commercial level. And so, in that interim 15 or so years, there was so much growth that I was able to experience from pursing the aspiration to be an artist. You lose maybe nine-tenths of your people that way, but that’s the tradeoff.

Let’s go back to the reunion. Christine, you had been out of the Mac world for some time. Was there any hesitation about returning?
McVie: I really had no doubts at that time when I reached out to Mick and said, “this is what I want to do.” I didn’t even feel nervous about it. I didn’t think I would ever leave again and I know I won’t.

Lindsey, you’ve referred to Mac as a musical soap opera. Yet there are artists who say the negative stuff falls away as you get older.  Is that what you feel like has happened for both of you?
It’s all baggage, John and I are really close friends now. I’m sure there’s always a bit of drama with us.
Buckingham: The very thing that makes us what we are, which is something greater than the sum of the parts is, to some degree, having the chemistry that makes us a bit of a dysfunctional family — whether we like it or not. That’s never going to completely go away, but you do learn to appreciate that some of that was responsible for us being able to do what we did. And, to some degree, in spite of that. I honestly think part of the appeal of “Rumours” was that it was sort of heroic. We managed to push through in the face of so much personal adversity. That was really at our doorstep during the making of the album and we had to compartmentalize.
McVie: I haven’t listened to it lately, but periods when I do listen to “Rumours,” which is not that often, I try to imagine how we ever finished it with what was going on. I still am amazed by that. “How did we ever do that?”
Buckingham: That very same thing, chemistry. But also being able to put aside all of that and find the fortitude, I don’t want to use the word heroism, but I mean, in a way, I think people, as much as they were intrigued by all the tabloid-ism, they were also inspired by the fact that it prevailed in spite of all that. Somehow we were able to follow our destiny and that spoke of all the collective inner strength that we had.
McVie: Also, I think people listening to it felt a lot of their own pain. They related to the songs somehow and, to this day, it’s timeless. It feels great to be able to play them again.

After all this distance, are there songs you have a new appreciation for?
McVie: I actually enjoyed making “Tango In The Night.”
Buckingham: Again, “Tango In The Night” was frustrating but it was also empowering for me because I was coming off having done “Go Insane” and we were embracing a certain kind of technology. And even though one might say that I had done the lion’s share of producing on all those albums, there was a kind of a dues to be paid. So you’ve got the first two albums, then you’ve got “Tusk,” where it says, “Special thanks to Lindsey Buckingham.” That was all begrudgingly given and that speaks of the politics of the band. By the time you got to “Tango,” no one was mincing any words about that. So that was empowering to be able to go in and have no one take issue with who was doing what and to sort of take the reins with a frame on it. Part of the reason was that everyone was in party mode permanently at that point, so that needed to be done. “Tango” was a good experience looking back on it, and it seems to hold up pretty well.

Talk about the juxtaposition then of doing these more intimate shows you’ll be doing as the two of you versus the massive Classic East and West shows.
It will be bizarre after doing all these 3,000-seat shows.
Buckingham: That is the complete extreme of scale.
McVie: I find [the stadium shows] less nerve wracking.
Buckingham: That’s clearly the big, big machine. I think of what we’re doing as the medium machine. Then I’ll do the small machine next January with a solo album. It’s nice to have it all.
McVie: I’m dying for that reunion, I think that’s going to be great.
Buckingham: Yeah, it will. And then of course the Mac will go back out sometime probably summer of 2018.