A hell of a lot has happened since Hot Press last caught up with Foo Fighters’ leader David Grohl. A significant box on the band’s bucket list was ticked when the Foos headlined Slane in 2015. Grohl, later on that same tour, broke his leg on stage – but gamely soldiered on, performing subsequent dates from a bespoke “throne”. As befitting his status as “nicest man in rock” (see below) he afterwards loaned the chair to a similarly incapacitated Axl Rose.

More tragically, this year he suffered the loss of his old grunge pal Chris Cornell, with the Soundgarden man hanging himself in May after a gig in Detroit. Mention of the latter naturally brings a lump to the throat of the thoughtful Grohl – who has gone through the suicide wringer once already with the 1994 death of Kurt Cobain and the tragic end of Nirvana.

“I just want everyone to survive,” says Grohl (48). “You cross your fingers and say your prayers and hope everyone makes it home safe at night. When you find out that you’ve lost a friend…” He trails off. Nirvana and Soundgarden were radically different, the former an indie punk trio that stumbled into fame, the latter an old-school stadium monster. Grohl was nonetheless close to Cornell, with whom he struck up an acquaintance upon relocating from Washington DC to Seattle in 1990 to join Nirvana. Thus began a life-long friendship. They finally had a chance to collaborate five years ago when the Foos man directed a video for Soundgarden’s 2012 comeback record, King Animal.

“The one thing I was pleasantly surprised with when I moved to Seattle was that the music scene was a community of friends that happened to play music,” Grohl recalls. “Whether it was Mudhoney or Soundgarden or Pearl Jam or Nirvana or Alice In Chains. Most of those people you could find at the same bar on the same night.”

When grunge exploded and industry fixed its gaze on Seattle, there was, he reports, a strong camaraderie among all the bands that had come up together.

“Everybody felt connected to everyone else in this beautiful way. Especially when the scene really started to blow up. You would bump into your friends from Seattle on the other side of the planet. You had something in common. Over the years I’ve made friends with Chris Cornell and all the Soundgarden guys. It’s like this big extended family of musicians that all happened to have the same incredible experience at the same time. You know, we’ve lost a couple of beautiful people – musicians – over the years. It just fucking breaks my heart.”

Cornell’s death, at aged 52, stunned even those close to him. Nobody in his life had suspected he was suicidal. Even now, five months later, his motives for taking his life are unclear.

“We were all shocked, fucking shocked,” says Grohl. “That was not one that I saw coming at all.”

The chipper drummer-turned-frontman is taking time out from a family holiday in Hawaii to speak exclusively to Hot Press. The interview precedes the release of Foo Fighters’ ninth studio album, Concrete And Gold. Written and recorded against the backdrop of the rise of Donald Trump, the LP is the most overtly political Grohl has yet assembled, with unease over the direction of the United States a constantly resurfacing theme.

As the father of three daughters, the existential crisis sweeping America clearly weighs heavily on his rock god shoulders.

“It’s such a heavy trip these days,” he says. “I’m a forward-thinking person. I’m not just thinking about my tax rates. I’m thinking about ocean levels, about the environment. Raising three daughters you wonder what’s going to happen in 30 or 40 years – and how the world we are living in today is going to affect it. It can seem really desperate and bleak. The challenge is to find hope in all of this. The lessons we are learning now will hopefully be taken into consideration in the future. The time period in which I wrote the album was just at the beginning of the political chaos.”

The Grohl family live on a two-acre estate overlooking Los Angeles’s San Fernando Valley. Southern California was deep in the tank for Bernie Sanders in the run-up to the election and to many of those with whom Grohl rubs shoulders, Trump voters feel like tragic weirdos from another planet. He, however, understands these people. After all, they were all around him when he was a kid.

“I grew up in Virginia, just outside Washington DC,” he says. “Go 20 minutes north and you are in this cosmopolitan political environment – the epicentre of cultural America. Go 30 miles south and you are in the woods. That’s blue collar, working class Virginia. I understand the frustration on both sides. I understand the frustration that everyday blue collar Americans are having just trying to get by. Just as I can understand the frustration that the other side of the aisle has.”

The Red State-Blue State split is something with which he is intimately familiar. Grohl’s late father was a conservative speech-writer. His mother, now aged 80, is a left-leaning retired English teacher (his parents divorced when he was seven).

“I was raised by a very conservative father and a very liberal mother. I understand both sides. The key is co-existence. It shouldn’t all be so black and white. It comes down to compromise and understanding and basic human respect. Sometimes that gets lost in these really broad banner messages. It’s a very fucking challenging time for everyone.”

Grohl caused a kerfuffle several months ago when telling a British audience Trump voters were “fucked” in the head. He’s more conciliatory speaking to Hot Press. The way he sees it, Foo Fighters are about bringing people together. In a churning mosh-pit, individuals of every creed, colour and political hue can unite as one.

“I got behind Hillary in the last election – personally and within the family we supported her as much as we could… And we supported John Kerry when he was running. The band did a few things for Obama. However, we have never really had an outward political presence.

“When we go play Kansas City or St Louis or Detroit… there are all sorts of people singing along for different reasons. And they come together as one in every chorus. Music is the perfect antidote to a lot of the tension. I’m very happy and proud that we’ve found our place where we can bring people together. It isn’t something I take lightly. I think about it all the time.”

When making the new album Grohl’s aim was to combine the stomp of heavy rock with the zing of pop classicists such as The Beach Boys (recording took place in the downtown LA studio where Pet Sounds was assembled and Nirvana Unplugged received its final mix). To that end, he recruited Adele/Pink producer Greg Kurstin (Adele’s ‘Hello’ is one of his jams). It was a decision that, putting it mildly, was met with raised eyebrows by the rest of the band.

“They were totally shocked,” Grohl remembers with a wry grin. “I went to them and said, ‘I think Greg Kurstin should do the record.’ They were like, ‘Who’s Greg Kurstin?’ When they heard he had done Sia and Adele and Beyonce and Pink the response was: ‘Are you fucking crazy?’ The thing is, he’s a musician’s musician. I knew he would take us to a place we always wanted to go but never quite reached.”

In addition to channelling Grohl’s political concerns, Concrete and Gold was a backlash against the frustrations he experienced recuperating from his broken leg (he sustained the injury tumbling off stage in Gothenburg on June 12, 2015 but naturally finished the show).

“We were fucking cooked after that tour,” he recalls. “Physically, emotionally, mentally – we all needed a break. I told everyone I didn’t want to talk about the band for a fucking year. Six months went by and I started losing my mind. It was ridiculous. I had a beard, I was in my pyjamas for days on end. Eventually I just picked up the guitar and started writing.”

As music icons go, Grohl is charming and self-deprecating. Still, he remains baffled by the “nicest man in rock” tag he acquired during Foos early years and has struggled to shake off.

“I always felt it was kind of the funny that I got the nicest guy in rock thing…,” he told me when we spoke previously. “I’m not a fucking saint you know. If I wanted to be a priest, I’d be a fucking priest… I always laughed at the nicest man in rock thing. Yeah, I could sit around in the pub and make you laugh for an hour. It isn’t that one dimensional. I’m a fucking human being.”

Grohl hopes to bring the Foos back to Ireland soon, for their first gig since headlining Slane. He has a long-standing fondness for the country – and not just because of his Irish American roots. After Kurt Cobain shot himself in 1994, Grohl never wanted to set foot on stage or in a recording studio again.

So he went on a driving holiday across Ireland and did his best to put memories of Nirvana behind him. The ploy wasn’t 100 per cent successful – when he stopped to pick up a hitchhiker one day he was amused/horrified to find the kid wearing a Nirvana t-shirt. Still, by the end of his Celtic sojourn he was ready to go back to being a rock star. He has ever since credited Ireland with helping him get his career back on track. “The Nirvana experience was such a whirlwind,” he says. “It all happened so quickly – exploded without any warning. And then it just disappeared. Life had changed so much it was almost like you had to find something to hold onto so that you didn’t get swept away. Once it was over, I couldn’t imagine stepping on stage or sitting down at a drum stool and playing music any more. It would just bring me back to the heartbreaking place of losing Kurt.”

Then he went to Ireland and the wounds began to heal.

“A long time went by where it felt that music was going to break my heart again. Then I realised that, actually, music was the one thing that was going to heal it. I had been recording music by myself for years without ever playing it for anyone. I thought that going down to the studio at the end of the street would be therapeutic. I didn’t think it would become a band – and I sure as fuck didn’t think it was going to be a band for 20 years.”

He is naturally wary of the cult that has built around Nirvana and its late singer. The last time we spoke he reminded me sharply that, though Kurt Cobain might be a cautionary tale for the rest of us, to Grohl he was a dear friend tragically taken before his time.

“You have to understand for me, Nirvana is more than it is for you,” he said. “It was a really personal experience. I was a kid. Our lives were lifted and then turned upside down. And then our hearts were broken when Kurt died. The whole thing is much more personal than the logo or the t-shirt or the iconic image.”

The music he has made with the Foo Fighters has run from intense to fiery to feel-good (the giddiness accentuated by their often playful videos). Behind it all, though, is a sense Grohl is trying to set right what went wrong with Nirvana.

“I felt I had to do it – to exorcise something in my soul,” he says of starting over with the Foo’s self-titled debut LP from 1995. “The intention of this band from day one has always been to keep the ball rolling: as musicians, as human beings, as friends. To feel like life keeps moving forward. We still feel like that every time we make a record – every time we step on stage. We feel like life is moving forward and that we’re not looking back.”

Grohl was pleasantly surprised Foo Fighters – essentially a solo project – took off. But the real breakthrough was in 1997, with the Colour And The Shape. On the 20th anniversary of the album that yielded such signature hits as ‘Everlong’ and ‘Monkey Wrench’, does he look back and think, ‘Wow that guy really had his shit together?’

“Hah no,” says Grohl, all trace of sadness leaving his voice. “I remember making that record while not having a place to live. I was sleeping in my friend’s back room in a sleeping bag. His dog would come in and piss on the sleeping bag every fucking night. The next day I’d go into the studio with [notorious taskmaster producer] Gil Norton and he’d make me do 30 or 40 takes.

“It was total fucking chaos. The fact we survived that means we could survive anything. I don’t even like to listen to that record. I love to play the songs live. But I listen back and it just gives me the fucking chills. It’s like, ‘Oh god, that dog was pissing on me every night’.”