When Slash was putting together the track list for his upcoming blues album, Orgy of the Damned, he had a very distinct voice in mind for his version of Fleetwood Mac’s “Oh Well”: Chris Stapleton.

“His singing cadence and that drawl that he has for this particular song, in my mind’s eye, it sounded perfect,” the Guns N’ Roses guitarist tells Rolling Stone.

But despite Stapleton having opened some shows for GN’R, Slash didn’t already have a relationship with the country crooner. “I had to get his number and cold call him,” Slash says. “And he was really gracious about it and really bent over backwards to help me get it done.”

It was a call worth making. Stapleton’s voice, one of country music’s most powerful, blends perfectly with Slash’s dirty blues playing on the song, written by Fleetwood Mac’s Peter Green and first released by the Mac in 1969. Says Slash, “I think it was one of the best ideas I’ve had in recent memory, was to have him sing that song.”

Back in 2016, Guns N’ Roses tapped Stapleton to open the Nashville date of their Not in This Lifetime reunion tour at Music City’s Nissan Stadium. Afterward, Stapleton talked to RS about meeting GN’R frontman Axl Rose and quizzing him on his vocal technique. “I asked him how many nights in a row he can possibly scream like that, and do all the high, high rock & roll singing that he does. Because I know for myself I have limits, and how many nights in a row I can actually sing,” Stapleton said. “Then we discussed him doing stuff with AC/DC a little bit. It was conversations you don’t think you’re ever going to have.”

Due May 17, Orgy of the Damned finds Slash teaming up with Billy Gibbons, Iggy Pop, Demi Lovato, and more. The first single, Howlin’ Wolf’s “Killing Floor” features AC/DC howler Brian Johnson on vocals and Aerosmith’s Steven Tyler on harmonica. Slash will re-create the album with various special guests on a summer tour he’s calling the S.E.R.P.E.N.T. festival.

(Reporting by Kory Grow)