As the frontman of one of the biggest rock bands on the planet, you might expect peoples' attention to be focused on your present-day endeavours rather than your former life. When you're Dave Grohl however, those lines can be a little blurred. It meant that when Nirvana were inducted into the Rock'n'Roll Hall of Fame earlier this year, the Foo Fighters leader had no issues with reflecting on that comparatively brief period of his life.

“I wouldn’t be here today if it wasn’t for Nirvana,” he says on the phone from a typically sunny Los Angeles. “I started Foo Fighters to keep life moving; I wasn’t sure what I was going to do after Nirvana, and I wasn’t even sure if I wanted to play music. Then I realised that music is my life and I needed something to help me get through that experience – so we started the band.

“You keep working and keep looking ahead and it quietens down again for a little while, and then another anniversary comes around,” he says. “But y’know, I’m incredibly proud of having been a member of Nirvana, and I’m happy that Kurt’s music lives on today in young generations of musicians.”

At the Rock'n'Roll Hall of Fame performance, Grohl, bassist Krist Novoselic and guitarist Pat Smear were joined by Joan Jett on Smells Like Teen Spirit, Kim Gordon on Aneurysm, St Vincent on Lithium and Lorde on All Apologies. It was, says Grohl, an "incredible trip down this nostalgic path . . . Krist and Pat and I hadn't played those songs since Kurt was alive – not even in private," he says.

“So to sit down and actually hear the sound of Nirvana in a room again, it was amazing. It was really emotional and I’m really glad that we did it, because of course, everyone just thought of Kurt the entire time – but in a beautiful, celebratory way. We were there to celebrate his music and to celebrate his life. So it was nice.”

Love reconciled

The Hall of Fame induction was also the scene of an unexpected reconciliation between Grohl and Cobain’s widow Courtney Love. It’s a contentious topic to bring up, I say, but my editor will kill me if I don’t ask . . .

“Awwwww no, you don’t wanna ask about that,” he says, deftly sidestepping the query with a guffaw. “Tell your editor that I’ll give him a big kiss the next time I see him – how about that?”

The conversation turns to his current projects. The word "busy" doesn't quite do Grohl justice. In the past two years alone, he has directed acclaimed documentary Sound City, about the history of the LA studio of the same name; he has completed the eighth Foo Fighters album and directed an accompanying TV series for HBO; he has produced an album for Swedish metal band Ghost; he has guest-hosted US TV show Chelsea Lately; he recently became a father for the third time; and he has played drums on any number of records by friends, including the last Queens of the Stone Age album. The phrase "annoying overachiever" was invented for a person like Grohl.

“There’s plenty I can’t do – just ask my wife. I’m not really good at changing the lightbulb,” he says with a chuckle. “No – I just find something that I have a passion for, and I race towards it and try to conquer it. And then once I have, I move on and find something else that I don’t know how to do. All of these things that I’m known for doing, I’ve never had any formal training for, and I still don’t technically know what I’m doing: I can’t read music, I never took lessons to play the drums, I didn’t go to school to write the arc of a story for a documentary, I never imagined I’d become a director – but once my head is in something, I can’t get it out and it stays there until it’s finished.”

Hit the sonic trail

The new Foo Fighters album, Sonic Highways, sees Grohl and his bandmates exploring the history of American music. The accompanying HBO documentary of the same name tracked their progress as they travelled around the country to eight famous recording studios, interviewed some iconic locals and recorded their own batch of songs, one in each city.

“The majority of the intention of doing a project like this is to let everyone celebrate music,” he says. “And not just the Foo Fighters’ music – but the music of Buddy Guy, the music of Public Enemy, the music of Zac Brown, the music of Joan Jett. I get to sit down with these people and listen to their stories, and deliver them to the rest of the world so that it will inspire the next generation of musicians to want to play.

"Rock'n'roll is a young man's game, and at this point I'm like the fucking Gandalf of rock'n' roll. It's getting to the point that I'm looking forward to that next wave that's just gonna fucking wash me out. It's coming, I can feel it. Hopefully this Sonic Highways project will kind of expedite that process."

The seeds of Sonic Highways were sown during the process for the last Foo Fighters album, Wasting Light, which was made in his garage. "We have our own studio where we've made a few albums, and when it came time to make the last record, I thought, 'well, rather than just do the same thing all over again, let's pull my minivan out of the garage, put a drum set in there, build a studio in the room upstairs and make the album there.'

“I wanted to see how the environment would affect the musical outcome, to challenge the band by making an album in a place that was outside our comfort zone, and see how that atmosphere would influence the music. And it worked: when I listen to that last record, it really sounds like these tight songs in a tight space and it has this aggressive tone to it, because that’s just what it sounds like in my garage, with bicycles and a refrigerator.

‘I’ll never do it again’

“So when it came time to make this record, I thought, Okay – rather than just challenge the band in one environment, how about eight? Rather than focus on one recording studio, how about eight? And rather than make one movie, how about eight? It was the most fucking work I’ve ever done in my entire life,” he groans, “and I’ll never do it again.”

Each city was chosen for a particular reason, not all of them personal.

“A couple of them have personal relevance; others, we went to discuss other things. In Chicago, the theme is ‘inspiration’. Washington DC, the theme is ‘community’, Nashville’s theme is ‘industry’, Austin’s theme was ‘gentrification’, Los Angeles was ‘creativity’, New Orleans is ‘survival’, Seattle is ‘starting over’, and New York is meant to be a sort of finale culmination of all of those ideas.”

The series took him to places such as Robert Lang Studios in Seattle, where Nirvana last recorded and Grohl recorded the first Foo Fighters songs in 1995. They visited Steve Albini's Electrical Audio in Chicago, and Inner Ear Studios in Washington DC, a mecca for the US punk scene of the 1980s. Artists as diverse as Joe Walsh of The Eagles, Ben Gibbard of Death Cab for Cutie and Joan Jett play on the album.

“Every city held a surprise. I learned something new in every interview, and I did about a hundred interviews,” he says. “It was an incredible learning experience: even if we hadn’t had cameras rolling the entire time, it would have been the most rewarding year of my life. I went to the spring and I drank from it; I got to go straight to the source and talk about the blues with Buddy Guy, and talk about country with Dolly Parton, and talk about rap with Chuck D from Public Enemy.

“You wanna learn about these things? Go and ask the people who fucking invented them.”

Did he feel a responsibility to chronicle this "love letter to America's musical history" in the midst of the American Idol generation? "I don't necessarily feel like it's a responsibility or an obligation, but I do feel drawn to the idea that there's more than just making records," he says, pausing. "There's more than just going out and selling T-shirts and turning on the smoke machines. To me, it seems like at some point, you need to give something back.

“I look at music programming today – especially in America – and it makes me worry that my kids aren’t going to get the same substance or depth in music. That it’s just going to become some kind of gameshow. And so, y’know, I was able to walk into HBO and convince them that my idea was valid, and they took a chance, and it worked.”

At this stage, you might wonder what Grohl might have left to achieve; when you’ve had a street in your hometown named after you, sold millions of albums and have the respect of your peers, what keeps the fire kindled?

“You know what? At this point, I just wanna learn how to make shrimp étouffée,” he says, without hesitation. “If I can make a good shrimp étouffée, I’ll be the happiest man in the world. Simple pleasures, man. That’s where I’m at.”

Foo Fighters play Slane Castle on  May 30th, 2015