For rock guitarist Slash, his first exposure to the blues happened without him even knowing it.

“It was British rock and roll in England that my dad was a follower of,” the Guns N’ Roses’ lead guitarist says of the music he loved as a child in Great Britain with his English father and American mother. “So it started with the Who, the Moody Blues and the (Rolling) Stones and all that kind of stuff.”

But when he was 6, the family moved to the United States, and Slash says his maternal grandmother decided to teach him a thing or two about the music he loved.

“My grandmother, who’s obviously American, was like, ‘That’s all great with all those British artists, but you know it all started here,’” Slash says. “She turned me on to B.B. King. I remember that specifically. And it really spoke to me. It was like, Wow, a real revelation.”

As a teenager in the late ’70s, he remembers loving American and British bands such as Aerosmith, Led Zeppelin, AC/DC and the Rolling Stones, whose roots were also in blues music.

All of which led to the moment he first picked up a guitar and started to play, Slash says.

“When I put those few notes together on a guitar, that were basically a blues lick, it was like the heavens parted, you know?” he says. “It was all inspired by my grandmother really turning me on to that first B.B. King record way back when.

“I didn’t know much about anything,” he says of his 7-year-old self when he had that blues epiphany. “It was the just vibe of it. Just the feel and the tone and the cadence of it.

“As I’ve gone on to play guitar, B.B. King has stayed with me as probably my favorite of all my favorite blues guitar plays. He’s sort of at the top of the list. And his guitar playing is something that I was majorly influenced by.”

Yet rock and roll became his career, first, as Guns N’ Roses made its name on the Sunset Strip in the mid-’80s before rocketing to worldwide fame a few years later. Then, after leaving that band for the first time, he had groups such as Slash’s Snakepit, Velvet Revolver, and Slash featuring Myles Kennedy and the Conspirators.

Today, Slash has been back in Guns N’ Roses since the band reunited in 2016. And a year ago, on a break in the GNR tour schedule, he and a few friends went in the studio to record an album of their favorite blues songs. His debut blues album, “Orgy of the Damned,” features different singers for each track, from Chris Robinson of Black Crowes and country star Chris Stapleton to Iggy Pop and Demi Lovato, Bad Company’s Paul Rodgers and AC/DC’s Brian Johnson to ZZ Top’s Billy Gibbons and Gary Clark Jr.

This month, he hit the road with Slash’s S.E.R.P.E.N.T. Festival, celebrating the new album and the blues with his own band and different guests on different dates.

Bar band blues

While playing huge stages in arenas and stadiums with GNR in the ’90s, Slash’s nights off in Los Angeles often ended in tiny clubs playing in the side project Slash’s Blues Ball.

“I do a lot of jamming, just sitting in with bar bands, and I have done for years and years,” Slash says. “At some point in the very early ’90s, I started meeting people in L.A. and some of the guys from Blues Ball were a couple of those guys who I started jamming with regularly.

“So eventually, I put together this cover band,” he says of Blues Ball, which formed around the time he left Guns N’ Roses in 1996. “It was inebriated and loose and cool songs. Just a great hang.”

Blues Ball never recorded — Slash says he still wanted to play hard rock as a career — “but in the back of my mind I still wanted to be able to play that style, which I do in my hard rock stuff, but something just a little bit more traditional.”

A year ago, with a three-week break in the GNR tour, Slash called his old blues buddies — keyboardist Teddy Andreadis and bassist Johnny Griparic from Blues Ball, and rhythm guitarist Tash Neal and drummer Michael Jerome — and went into the studio and got to work.

“I picked 10 songs and had the idea of getting the outside singers as opposed to Teddy and Tash and me,” Slash says. “Just to make it not a strictly focused blues record that everybody was thinking, oh, I’m jumping on the blues bandwagon now. I didn’t want to give that impression. I just wanted to do this for the fun of it.

“We had a week to record the whole record,” he says. “So we went in and knocked it out, and it was just a lot of fun.”

When “Orgy of the Damned” was released on May 17, it debuted at No. 1 on the blues charts in both the United States and United Kingdom.

Songs and singers

Many of the songs Slash chose for the record were part of the Blues Ball’s repertoire in the ’90s, standards that had deeply influenced him as a musician over the years.

“I picked songs that I had listened to as long as I can remember, and had a big influence, like a guitar riff or whatever it was that was part of my DNA,” Slash says.

The early Fleetwood Mac song “Oh Well,” Robert Johnson’s “Crossroads,” and Howlin’ Wolf’s “Killing Floor” weren’t part of the Blues Ball’s old sets, but were big influences and songs he’d always wanted to play. (They are sung by Chris Stapleton, Gary Clark Jr. and Brian Johnson, respectively, with Aerosmith’s Steven Tyler playing harmonica on “Killing Floor,” too.)

“‘Born Under a Bad Sign’ was that Albert King style, another one of my favorite guys,” Slash says of the song done here by Paul Rodgers. “That sort of riff was such a big part of my playing direction when I was a kid. So I had to do that one.

“I chose to do ‘Living for the City’ because it was my favorite Stevie Wonder song when I was a kid,” he says. “One of the songs that we did that was covered a lot, but I still wanted to do it, was ‘Key to the Highway.’ That was one of the songs that brought Teddy and Johnny and I together back in the day when I first started jamming with those guys. We do more of a Freddie King stylized version of that.

As for the singers on each track, Slash says he’d pick the song and then think who should sing it.

“Seriously, everybody who’s on the record were the first people I thought of,” he says. “The only person that I wasn’t on the record that I wanted was Lemmie (Kilmister of Motörhead, who died in 2015). It really brought it home to me that I couldn’t call him, because he would have been great.”

While Gary Clark Jr. and Beth Hart are more purely blues artists, others such as Iggy Pop — the godfather of punk — and Demi Lovato — a pop star with Disney Channel roots — are less expected.

Summer blues

S.E.R.P.E.N.T. Festival – the acronym stands for Solidarity, Engagement, Restore, Peace, Equality N’ Tolerance – reflects a lifelong love of summer festivals, Slash says.

“I have a sentimental thing for summer festivals, ever since I was a kid,” he says. “I’ve always loved that, you know, getting people together and just having a day of music and a couple of beers. And just being out there to listen to music all day.

“So that’s one of the things,” he says of the summer blues tour. “But then the other is just being able to go up there and play and do this thing that I love to do, and just have a really great time doing it. That’s my expectation.”

The dozen songs on “Orgy of the Damned” will be supplemented by other blues classics, he says, but the freedom that music offers its players might lead anywhere, Slash adds.

“There is a huge element of danger to this because we don’t know what we’re doing,” he says and laughs. “It’s just throwing it together and paying attention to what’s going on, but at the same time, not trying to overthink it. So for me, it’s going to be a really new experience."