The first voice I hear when I enter the hotel room to meet Kate Hudson belongs to her 21-year-old son, Ryder, who speaks from the end of a phone: “Love you, Mum!”

Doesn’t everyone? You don’t have to be related to Hudson to consider her a joyous proposition – a great performer who hasn’t yet made a great film. It was a quarter-century ago in Almost Famous, her breakthrough picture, that she first proved she could hoist a movie out of the doldrums while making the task appear as effortless as blow-drying her hair. Without her performance as Penny Lane, the rock’n’roll muse who describes herself as a “band-aid” rather than a groupie, Cameron Crowe’s dopey valentine to the 1970s of his youth would have been Almost Forgettable.

Her vitality propelled that film, and her face alone drove its marketing campaign, so it was only right that Hudson, then just 21, received an Oscar nomination. The years that followed brought a confetti-like flurry of romcoms, including How to Lose a Guy in 10 Days and Bride Wars, both smash hits despite their mood of seething bitterness. There were overlooked dramatic gambles (The Killer Inside Me, The Reluctant Fundamentalist), maximum-cringe misfires (the cancer weepie A Little Bit of Heaven, Sia’s crass autism drama Music) and the odd effervescent comeback, including Glass Onion: A Knives Out Mystery, in which Hudson was superb as a dim-bulb fashion designer prone to facepalm moments.

Now 46, she has just received a Golden Globe nomination and likely has another Oscar nomination on the way. Once again, it is for a movie steeped in music: Song Sung Blue, a real-life underdogs’ love story based on the 2008 documentary of the same name. Hudson is Claire Sardina, AKA Thunder, who forms a Neil Diamond tribute outfit with her husband, Mike (Hugh Jackman), the Lightning part of the duo. The opening half, in which Claire meets Mike and pushes their collaboration from musical to romantic, is pleasantly nutty. The remainder has more tragic twists than a doom-laden country and western standard. Through it all, Hudson is a beacon of resilience, humanity and tenderness.

Dressed all in black today, with straight, glossy blond hair, she is relaxed, if easily distracted. “Should I eat this if it was already open?” she wonders aloud, inspecting the sachet that came with her tea. “Do you think someone did something to this?” She tips the contents into the cup all the same. “Cut to the end of the interview and I’m, like, on the floor …”

Hudson also has one eye on what she and her son are doing later this evening. “We’re going to see Radiohead. I’m so excited!” The last time she saw them live, she was Ryder’s age: it was October 2000, Almost Famous had just opened in the US, and the Oxfordshire avant-gardists were the musical guests on Saturday Night Live, which she was hosting. Hudson threw off her clothes to reveal the words “Radiohead is here” daubed on her bikini-clad body along with flowers and peace symbols. To the sound of frantically groovy music, she bopped and shimmied while the camera zoomed in and out at high speed.

The entire spectacle was a reference to Rowan and Martin’s Laugh-In, the giddy late-1960s comedy show that made a star of her mother, Goldie Hawn, who was typically seen cavorting in swimwear and body paint. That SNL moment was also an early acknowledgment, as if any were needed, that Hudson would have her work cut out trying to escape her mother’s shadow.

Hawn is an invisible presence in this London hotel room. It is her 80th birthday, and Hudson is missing the celebrations back home in favour of promoting Song Sung Blue. At least she can feel symbolically close to her mother by being in the city where it all began. “It’s so awesome that I was conceived in London,” she says, ignoring the teatime rain clattering against the window. Conception occurred in Regent’s Park, about a mile from where we are sitting. “Not in the actual park. That would have been a way cooler story. It was in an apartment my mom was renting. I bet she’ll remember which one.”

Her parents – Hawn was married to the musician Bill Hudson – split when she was 18 months old and her brother Oliver was four. Their stepfather, the actor Kurt Russell, whom their mother has been with for more than 40 years, is the man they call “Pa”. Asked last year about her relationship with her biological father, who blasted her as “spoiled” in his memoir but was largely absent from her life, Hudson said: “I don’t really have one.” She then modified her statement: “It’s warming up.”

Music has been the connective tissue throughout her life and work. Bill Hudson was a member of the Hudson Brothers, who spent much of the 1970s as teen idols signed to Elton John’s record label. Hawn released a country-tinged album, Goldie, in 1972. All three of Hudson’s children have musician dads: Ryder’s father, and Hudson’s first and only husband so far, is the Black Crowes singer, Chris Robinson; she had her second son Bingham, who is 14, with Matt Bellamy of Muse; and her current fiance, Danny Fujikawa, formerly of the LA band Chief, is the father of her daughter Rani, who is seven.

Hudson has sung on screen plenty of times before, including a boozy duet with Matthew McConaughey of Carly Simon’s You’re So Vain in How to Lose a Guy in 10 Days, and the showstopping sequence in Nine in which she belts out Cinema Italiano while trooping up and down a catwalk in silver boots. “WHY hasn’t a musical been written for Kate Hudson?” demanded one YouTube commenter, not unreasonably.

Song Sung Blue is different. The Neil Diamond numbers are all wrapped up in Hudson’s performance: she’s singing in character, expressing Sardina’s pain, yearning and indefatigability through music. “In the studio, I’d find these harmonies myself and do my own vocal riffs,” she says proudly. The director, Craig Brewer, encouraged her. “I’d be saying, ‘But Craig, is it really Claire?’ And he’d go, ‘It is now!’” That latitude may not have been possible had she modelled herself too closely on the real Sardina, whom she only met when shooting was under way. “By that point, my version of Claire was in my body. But it was good to have her there to ask, ‘Did this bit really happen like this?’”

Hudson’s singing in the film has more authentic gusto than anything heard on her own rent-a-rocker debut album, Glorious, released last year. It was while promoting the album on US television that she caught Hugh Jackman’s eye. “Hugh saw me being interviewed, where I’m talking about how I simply had to be singing and writing music, and he was like: ‘Well, she obviously needs to be Claire.’” You can see his point. It’s the urge to perform that sustains Sardina as fate dishes out one flabbergasting blow after another. “I understand what it’s like to love something so much that you can’t face losing it,” says Hudson.

She might not have recorded Glorious in the first place if it weren’t for Paul McCartney. “It was Paul’s 80th birthday and I was sitting at the side of the stage watching him headline Glastonbury.” The story ends in an epiphany. “I woke up the next morning and felt so emotional. I was, like, ‘I am not happy with my output!’ I mean, I have so much gratitude. But I am not just an actor. I’ve been a musician my whole life and I never had the courage to do anything with it. I decided I want to take more chances. I want to fail more.” Perhaps she won’t be too hurt, then, that the Times described Glorious as “the very essence of a vanity project”.

Watching McCartney made her think “about those who compromise and those who don’t. I thought about being a woman in the industry and all the compromising you do for other people. About doing comedies and being successful in them but still feeling like you’re constantly having to compromise.”

Not that she’s dissing romcoms. “You know what? They’re my favourite. I love them and I will never stop making them. I just think they need to be better. When you’re trying to make a great one, you’re fighting a lot of algorithms. I think they’ve dumbed down the romcom. The ones I loved were written and directed by the best talent. Nora Ephron, Jim [James L] Brooks: those are the great ones that last for ever. They’re like comfort blankets.”

Other films are more like hair shirts. Take The Killer Inside Me, a necessarily repulsive adaptation of Jim Thompson’s noir novel about a psychopathic deputy sheriff, played by Hudson’s old pal Casey Affleck. It was Affleck and the picture’s British director, Michael Winterbottom, who persuaded her to take the role of the killer’s fiance, who is shown being spanked. For real, as she confirmed in 2010: “There were a couple [of slaps] in there when I thought: God, Casey! He got a bit of power behind it.” Before being murdered by him, she is spat on and punched in the stomach. It’s a contentious film but hardly the work of a compromiser.

“That stretched different muscles,” she says now. “I didn’t get into acting to only do one thing.” Affleck intimated at the time that his then wife was no fan of the film. What feedback did Hudson receive? “Oh, it was fine. It was such a small movie.” Meaning, presumably, that no one saw it anyway. I tell her I admire it, but I never want to watch it again. “That’s how I felt,” she says.

She claims not to pay any attention to what is said about her, good or bad. “It all falls into the category of what Kurt calls ‘noise’. His thing is always: just do great work.” Presumably, that goes for all the Oscar chatter, too. “That’s nice noise,” she concedes. I ask how often she has been checking Variety magazine’s regularly updated Oscar predictions. Should I get them up for her on my phone? “No, don’t!” she squeals in horror. “It freaks me out. I can’t even.” I refrain from telling her that Jessie Buckley is the current favourite to take the prize for Hamnet. Where Buckley’s performance as Shakespeare’s wife, grieving the death of their young son, is studied and self-consciously elemental, Hudson’s work in Song Sung Blue has an undemonstrative fluidity. It feels like life, rather than acting.

Nomination or not, she has plenty to keep her busy, including Sibling Revelry, the family-dynamics podcast she co-hosts with her brother Oliver. Guests have ranged from A-list (Michelle Obama and the occasional Kardashian) to niche, such as the “psychic medium” John Edward. He was credulously indulged across two hour-long episodes, egged on by Hawn, who is no stranger to psychics; and Oliver, a garrulous sometime actor who claims to consult oracles before choosing whether to accept a role. Let’s just say this doesn’t reflect well on the oracles.

Hudson is not quite so woo-woo. “Psychic readings are fun,” she says. “But I take them with a grain of salt.” On a recent episode, the siblings were diagnosed with ADHD live on air by a doctor who didn’t seem entirely sure who he was speaking to; at one point, he mistook Oliver for Hudson’s partner. Was it an official diagnosis? “Oh yeah, it was real.” She says she found it “validating. I’ve spent for ever trying to figure out how to organise my life and now I feel I have the tools.” She distinguishes their diagnosis from what she calls the general ADHD of the world: “the kind that’s due to phones. What we have is the real deal.”

Her next goal for the podcast is to quiz more directors. Turning the tables on me, she asks: “What kind of interviews do you like best? Who’s been your favourite?” Then a comical flutter of the eyelashes. “Apart from me, obviously.” But the experience of being interviewed by Hudson is over before it has begun. Time’s up, and Radiohead are waiting. As for her career: here’s hoping for more alarms and more surprises, please.

• Song Sung Blue is in UK cinemas from 1 January

• This article was amended on 15 December 2025. Kate Hudson’s eldest son is named Ryder, not Tyler as an earlier version said.