John Grant makes the kind of music that changes lives. Sometimes even saves them. In his big, baritone voice, he sings – with a candour that stops you in your tracks – of lust, love, addiction, oppression, HIV and self-loathing. British singer-songwriter Tom Robinson, one of the very first rock musicians to come out as gay, believes that if Grant had been around in the Sixties, “he could have saved me 10 or 15 years of heartache and pain”.

“Mmm, that’s lovely,” says Grant, swilling a glass of icy water. We’re in the beer garden of a London pub, sheltering from the sun at the shady end of a wooden table. It’s taken no time at all for the conversation to become intense. Grant is a warm, wry presence – all bear hugs and belly laughs – but just like his music, he is immediately, startlingly frank; ripping himself open at every turn and casually inviting me to have a look.

Grant knows better than anyone the solace that music can provide. Growing up in a conservative, religious town in Michigan, he listened to Culture Club in secret, sensing a kinship with Boy George before he even understood why. It was only in his mid-twenties – around the time he joined alt-rock band The Czars – that he came out as gay.

Since then, his music has tackled those years of denial, the source of his self-suppression and the joyful, painful consequence of finally living openly. “I can’t believe that I’ve considered taking my own life,” he sings on “JC Hates Faggots”, one of the best tracks on his debut solo album Queen of Denmark, “‘Cause I believed the lies about me were the truth.”

Unlike Robinson, though, Grant doesn’t think any band or person could have prevented his years of pain. “I don’t know whether I would have been able to hear it if it had been there,” he says. “I mean, I was so determined to not let homosexuality be the reality of what was going on with me, because it was a death sentence; it was a gateway to a horrible life, I thought. There were people that reached out to me, like my theatre teacher. She really wanted to tell me that it was OK, but she knew that I was gonna tell her to f*** off, because I didn’t wanna have it be true for myself.”

Instead, Grant found himself trying to “cultivate a masculinity, in order to not stick out like a sore thumb, so that I wouldn’t be attacked as much”. Today, his burly, bearded aesthetic is such a trademark that you wouldn’t think any part of it had been born out of fear.

“It’s so deeply ingrained in me,” he says, “thinking about posture, thinking about the way I walk. I still have trouble walking in public – I feel like I’m gonna be attacked for doing it wrong. When I see a group of teenagers walk by, I still go back to, ‘I’m gonna be attacked. Because I look like a faggot.’ And a lot of that is gone, but you’re still reacting and projecting what happened to you. I think it resulted in me having an anger problem. I mean I have a total problem with anger because of all that crap.”

There are times when Grant wishes he could have been as provocative and defiant as his childhood hero: “I say to myself sometimes, ‘Why couldn’t I be Boy George?’ It always felt like he was able to be himself, from an early age. He just went and found his community. He just moved away from home and went and found it for himself. I used to beat up on myself, like, ‘Why couldn’t you be stronger? Why couldn’t you just not give a f***?’

“But that’s pointless,” he concludes. “People deal with things in different ways. I was quite sensitive. And I’ve learnt that my sensitivity was not a negative thing, something to be crushed by alcohol and drugs in order to toughen myself up for the world.” Not that he didn’t try that approach. For over a decade, Grant used alcohol, drugs and sex to steel himself and numb his real feelings. He realised he needed to clean up his act 14 years ago, when he was diagnosed with such advanced syphilis that the doctor asked to bring in a team of student doctors to observe it. That same day, he started going to AA. “Getting sober 14 years ago,” he says, “was the beginning of me taking responsibility for my emotions and feelings.”

On his new album Love Is Magic, a gorgeous cacophony of lush strings, staticky synths and disco frills that channels the likes of Eurythmics and New Order, he attempts to do the same. “I would say all of me has been expressed in the record,” says Grant. “The kind, compassionate me, the defensive, scared me, the self-loathing me, and the one that’s being gentle with his inner child.”

On the robotic refrain of “Diet Gum”, between spoken-word diatribes delivered in a stumbling, self-mocking tone, he declares: “I manipulate, that is what I do / I manipulate, that’s what I’m doing to you.” The song might seem absurd, he says, “but it’s quite revealing. I’ve been nasty to people like that. And then you think about it later and you’re like, ‘What the f*** was I doing?’ It’s about anger, it’s about lusting after people and forgetting everything that you know, all your wisdom, just to have that thing, or forgetting that they’re a user or a narcissist, because you’re basically just a vapid c*** at heart.”

I wonder if he’s referring to the six-month relationship around which his second solo album, 2013’s Pale Green Ghosts, revolved. He doesn’t say, but he acknowledges that the effects of those six months – his first sober, adult relationship – were life altering. “It was a very short thing, but it opened up this abyss inside me where I was able to see how broken I was,” he says.

“That’s what that relationship did to me. It was never about that person, because six months is nothing, but it was about what it did to me, what it opened up inside of me – this ability to see this brokenness in a way that was terrifying. It caused me to go into a horrible tailspin, where I felt like committing suicide because I felt like I was too far gone to ever be able to learn to do it in a healthy way. I felt like, ‘If I can’t learn to love, in a way that doesn’t hurt me and other people, then what is there to look forward to?’” He has his subsequent relationship – with an Icelandic graphic designer – to thank for changing his mind, and for the bursts of optimism on his new album.

“Love is magic, whether you like it or not,” he sings on the album’s graceful title track, which sits atop an electronic soundscape evocative of Labyrinth-era Bowie. “When the door opens up for you / Don’t resist, just walk on through.” Those might sound like the words of someone happily, even smugly, coupled up – but in fact, Grant’s relationship recently ended.

He doesn’t regret it though. “One of the great things about it was my ability to love the person while letting go of them,” he says. “And that is something that I didn’t think I would be able to do. Because I didn’t want to break up with them. It was them breaking up with me, because of not being able to deal with my deep depression coming back from tours, and me imposing schedules on myself that made it impossible to really be there for that person.”

After the breakup, Grant kept asking himself the same question: “Why didn’t I f***ing do better?” But he has since decided to go easier on himself. “The truth is that I did the best I could,” he says, “and we were loving and respectful towards each other pretty much every day of those four years. There wasn’t any fingerpointing or nastiness, it was true respect for the other person. I guess that’s the difference that I see.”

That’s what inspired “Is He Strange”. “It’s just good to know,” sings Grant, “that you can love while you are letting go.” Although he knows now that his fears about love were unwarranted, Grant is happy being single for the moment. “I don’t feel like a lesser person to not be in a relationship,” he says. “I just turned 50, and sometimes I’m tempted to say, ‘Urgh, you’re f***ing 50 and you still don’t have it together?’ And I can say, ‘Well no, I’m a whole person whether I’m in a relationship or outside of a relationship.’ There’s problems with being single, and there’s problems inside relationships, that aren’t enviable so enjoy whatever you’ve got.”

Grant celebrated his 50th birthday riding rollercoasters in Cedar Point in Ohio, where he used to go with his mother (who died in 1995) in the Seventies. “I went back with my brothers and my sister,” he says, “and there’s a lot of Trump supporters in my family, but we all got along really well. We didn’t talk about that. We just were kind. I was really worried about it. I was really worried that it would be like, the end of relationships and stuff, but I love my brothers and I love my sister terribly.”

Does it worry him, knowing that there are kind people in the world who still voted for Donald Trump? “I go back and forth,” he says. The one thing he is sure about, though, is that “there’s gonna be something worse than him. It’s not like he has political convictions,” he says. “He’s just an attention whore.

So when the people that are controlling him get into power, that’s gonna be a whole different ball of wax, and a nastier ball of wax. But I don’t feel very optimistic about it. There’s people who think things are getting better and better, and in some ways I suppose it seems that way, but in a lot of ways it just seems like people are getting stupider and stupider.”

He catches himself. “But then we have tons of people around us who are incredible, right? And who we would trust our lives with. So it’s not hopeless.” More and more these days, Grant’s able to see hope – even in the darkest of circumstances. His new album reflects that.

“Well, it was an incredibly joyous experience making this record,” he says. “I mean, I always want the darkness to be there, because it’s an important part of being human – but I don’t think there’s anything wrong with letting more light in.”

Love is Magic, the new album by John Grant, is out on 12 October

The Independent