Robert Plant recently explained how he wanted to flee from the tryout session with Alison Krauss that led to their award-winning 2007 album Raising Sand.

He said he was already feeling out of his depth in having to sing a set melody so that Krauss could duet with him because he never was restricted that way in Led Zeppelin.

In a recent episode of the Broken Record podcast, Plant told Rick Rubin how the singers performed together at a gala event, and both felt there might be more to explore musically. Knowing they were “so radically different” as artists, they invited producer T Bone Burnett to play the role of “master magician,” although Plant “didn’t know what [Burnett] was going to be all about.”

You can listen to the interview below.

The trio agreed to try four songs over four days and gathered at Krauss’ Nashville home. “The door flung open, and there was Alison being really charming,” Plant said. “And behind her, this big imposing shed, John Henry Burnett! So I went, ‘Shit! … There’s two of them!’ They said, ‘Come in! What key?’ I said, ‘I don’t know what key; I don’t know what key anything is!’”

He sat down and enjoyed a cup of tea, then thought, “OK, where’s the microphone? Where’s the reverb, where’s the slap-back ... where’s the 45-millisecond delay? Where’s my stuff?” But he realized "there was nothing, there was just two couches and an acoustic. … And I felt so exposed and vulnerable. ‘How do I get out of here, man?’ … I could feel the moisture at my brow. ‘I’ve gotta get out of this place!’”

But Plant persevered and later went to a nearby studio to lay down four tracks with their complete backings. “The four days came and went,” he said. “I fled to Clarksdale!” While on the drive he listened  back to the recordings and thought, “Wow, this is really cooking!”

"It blew my mind when I heard it," Rubin said. "Mine, too!" Plant replied.

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