Robert Plant and Alison Krauss reflect on their collaboration ahead of their tour

SCOTT SIMON, HOST:

Duos can make something amazing - Batman and Robin, Simon & Garfunkel, Michael Jordan and Scottie Pippen, and our next guests, Robert Plant and Alison Krauss.

(SOUNDBITE OF SONG, "GONE GONE GONE (DONE MOVED ON)")

ROBERT PLANT AND ALISON KRAUSS: (Singing) Everyone that you meet, baby, as you walk down the street, baby, will ask you why you're walking all alone and why you're on your own. Just say I'm gone, gone, gone, gone, gone, gone, gone.

SIMON: Giant figures of rock and roll and bluegrass came together in 2007 for the album "Raising Sand." It was critically lauded. It swept up five wins at the Grammys, including album of the year. In 2021, they released "Raise The Roof." This weekend, they begin a tour across the country with nearly 40 stops. Robert Plant and Alison Krauss join us now from their rehearsal space ahead of the tour. Thanks so much for being with us.

ALISON KRAUSS: Thanks.

ROBERT PLANT: Great pleasure.

KRAUSS: Thank you.

SIMON: When, how, way, why did you two meet and decided you wanted to work together?

PLANT: There was a TV program called "Crossroads" where the least likely people were put together to see what sort of mishmash or what sort of end result could come from that, what could we aspire to. And I loved Alison's voice from a long, long way away on the Welsh borders, where I used to hear her on the British radio, and I really liked the idea of putting myself in a position to be exposed to a totally different process and a different kind of music and a beautiful voice.

KRAUSS: When we first talked about getting together, the only thing I had to go by is that he knew this song called "In The Pines." And I thought, well, he knows that song. We'll see.

PLANT: He can't be all dumb. Yeah.

KRAUSS: But, you know, like, you don't know what you're going to have in common. And I remember meeting him for the first time, and the first thing he talked about was Ralph Stanley and this particular record that all of the bluegrass community loves and holds so dear as one of the best records ever made. And he knew all about it and was talking about it, and I thought, we're going to be fine.

(SOUNDBITE OF SONG, "IN THE PINES")

THE STANLEY BROTHERS: (Singing) In the pines, in the pines where the sun never shines and you shiver when the cold wind blows.

SIMON: Ralph Stanley was big in Wales?

PLANT: Well, no, but I was intrigued because the exchange of songs between Black and white communities in what you'd loosely call the United States - it's quite phenomenal, really, because these songs interchange and they interreact. And so I couldn't see any reason why myself and Alison couldn't interreact because, somehow or another, we have common strains that exist in our taste, and it was just seeing whether or not we could apply it.

SIMON: Alison Krauss, you've worked with a lot of musicians - I'm going to use the word carefully - who are considered geniuses - Yo-Yo Ma, Willie Nelson, James Taylor, Kacey Musgraves. How do you collaborate? Do you have any rules about that?

KRAUSS: Well, I love it. I probably like it more than anything, getting to sing with someone else. And, boy, that's really interesting. I like paying attention to how someone ends their words or when they put the consonant at the end of the line, how long till they wait to put that. I sang with Johnny Mathis years ago, and he would put the N on the end of his word much sooner than anybody else I'd ever heard, and it was beautiful.

And that whole process of trying to match someone and match as close as you can - 'cause that's, you know, kind of the whole life of people who play this kind of music I grew up in, bluegrass, where your whole goal is to try to become a sibling of the person you're singing with. You know, I'm hanging off the edge of a cliff, listening to people through the headphones to see what I can match and complement. You know, that's my whole job, is to try to complement the other person.

(SOUNDBITE OF SONG, "KILLING THE BLUES")

PLANT AND KRAUSS: (Singing) I hope you never do because there is nothing sadder than losing yourself in love.

SIMON: Robert Plant, how do you create these harmonies?

PLANT: I don't create them. I'm a student. I would have had no idea how to go about the sort of interweave and the exchange of who's taking the lead on a vocal on a song. In fact, you're absolutely right, Alison was prolific about that whole idea of matching. Well, in my case, as a schoolboy from England, what was I trying to match listening to Robert Johnson? I wanted to strain out and wring out the emotion. There's something absolutely magnificent about those performances. But my limitation was I was a white young grammar school boy in the middle of England, obsessed by something I couldn't understand.

SIMON: Alison Krauss, what lifts you up about this partnership?

KRAUSS: It's completely unique. He is as spontaneous a singer as I've ever met and I'm sure the world has ever seen. And to try to understand that, going down, it's like almost all the other rules that I grew up with don't exist. And I have to abandon a lot of things I grew up with as my process of learning somebody's voice. And it really does take on a life of its own, and watching Robert in the studio as this all went down, you know, I had a lot of moments that were real epiphanies about my own singing and my own recording.

(SOUNDBITE OF SONG, "KILLING THE BLUES")

PLANT AND KRAUSS: (Singing) Bouncing over a white cloud, killing the blues.

SIMON: You learn from each other.

PLANT: Yeah.

KRAUSS: I'm still trying to.

PLANT: That thing that you were saying, Alison, about extending vowels and rolling consonants and that whole thing - it's such a trip to achieve it spot on. We look at each other, and Alison's left eyebrow lifts in approval sometimes because sometimes we can really do that thing that she lives for. And sometimes we decide that we might cut loose and just go off into infinity in some of the more dramatic moments where you just have to leave reason behind.

(SOUNDBITE OF SONG, "THROUGH THE MORNING, THROUGH THE NIGHT")

PLANT AND KRAUSS: (Singing) But to know that another man's holding you tight hurts me, little darling, through the morning, through the night.

SIMON: You two are really both historic performers, so I feel moved to ask you this. After all these years of performing, what do you think music puts into our lives?

KRAUSS: I always think it's a place to dream.

PLANT: Both giving it and receiving it, it's a puzzle. It's a great joy. I think sometimes, maybe as musicians, we may spend far too much time considering all the elements of it instead of just lying back and, as Alison says, just taking it as all part of a beautiful dream. It's the diversion from what we really see going on.

SIMON: Does it get into your soul?

KRAUSS: I think you're born with it already there, really. There's that place, I think, in everybody that music has a spot for. And not everybody's is the same, you know, but I think we're already born to receive that.

PLANT: Yeah, and the communion within it all, it's just magical and never to be taken for granted.

SIMON: Robert Plant and Alison Krauss. They begin their tour this weekend in Oklahoma. Thank you both so much for speaking with us. Happy travels to you.

PLANT: Thank you.

KRAUSS: Thank you very much.

(SOUNDBITE OF SONG, "CAN'T LET GO")

PLANT AND KRAUSS: (Singing) He won't take me back when I come around. Transcript provided by NPR, Copyright NPR.