Robert Plant and Alison Krauss Had 'No Expectations' Making New Album: 'Knew It Would Be Good'

After you reach the pinnacle of success, what comes next?

For Robert Plant and Alison Krauss, the answer was a 14-year pause following the surprise success of their 2007 collaboration Raising Sand, which won six Grammys, including album of the year.

And even though the legendary Led Zeppelin rocker, 73, and the bluegrass darling, 50, are back in action once more on the new record Raise the Roof, out Nov. 19, that doesn't mean they're letting their past achievements hang heavy.

Krauss and Plant tell PEOPLE in this week's issue that despite the massive popularity of Raising Sand, they felt "no expectations" when it came to joining forces for a second time.

"The only thing that I knew is that it would be good," Krauss says. "The songs were beautiful. I knew that our singing together has something that's very different."

Quips Plant: "And sometimes it's in tune. Once I've been told what to do."

Though an unlikely duo — he a rock god, she a country superstar —their friendly chemistry provided the perfect starting point for a fruitful partnership that began after they first met in 2004, when Plant invited Krauss to join him in a tribute concert for Huddie "Lead Belly" Ledbetter.

Plant says the way Raising Sand took off was "quite a shock," and something he "wasn't ready for."

"I really enjoyed the explosion of Raising Sand," he says. "And at the end of it all, the idea of gambling straight into something else was… It's a natural knee-jerk to do that. But we thought about it, romanced it, and then went back to our old-time used-to-bes. But we kept exchanging, contacting, sending a few musical ideas."

For more on Robert Plant and Alison Krauss, pick up the latest issue of PEOPLE, on newsstands Friday, or subscribe here.

Though they'd kept up a friendship over the years and always discussed recording again, Krauss says it wasn't until she heard the song "Quattro (World Drifts In)," which would go on to be Raise the Roof's opening track, that her creative spark was reignited.

"I thought that was the first song of our record when I heard it," she says. "I thought, 'A-ha!' We always talked back and forth about recording again together. And this was just the right time. Any other time, I suppose, was the wrong time, because it didn't happen."

She and Plant went on to record 12 new tracks for the album, all covers just like last time, save for "High and Lonesome," an original that Plant wrote with the album's producer T Bone Burnett.

"It's so much fun to bring things you've held onto and bring it to the table, and then see it come to life again in a new way," says Krauss. "The whole process together has been a surprise from day one, when we first met and made that first record. And then here we are again. The whole thing's been a surprise, and not with any expectations, which makes the whole thing a joy."

Raise the Roof was largely recorded in late 2019, and completed in early 2020, just before the pandemic hit, meaning its release has been a long time coming for the musicians.

"The time in between doing it and getting to this point has been very, very strange," says Plant. "It's like sitting on an egg that just won't open. And then you start wondering, 'Are we OK? Is it right? Does that sounds OK?' It's all that stuff. Everybody's been in suspended animation everywhere… But I think we cracked the record long before the lockdown."

Raise the Roof is out Nov. 19.

For more from Robert Plant and Alison Krauss, pick up the latest issue of PEOPLE, on newsstands everywhere Friday.