She shot the Beatles in 1963 and found them “very bright and interesting”. Not long after, she captured Bob Dylan, still just in his 20s, and recalls: “I think I was the only photographer at the gig.” Then, in 1967, there was Jimi Hendrix, who got slightly more than an interview and a shoot. “He was a very nice, gentle man,” Wilmer remembers. “I even gave him a lift in my car!”

It is surprising, given that some would give their eye teeth to have been at these performances, to hear what Wilmer has to say about their music. “Jimi was playing the Royal Albert Hall but I didn’t stay for his performance,” she admits. “I recognised he was a great guitarist, but I just didn’t have much interest in rock music. I probably went off to Ronnie Scott’s instead.” Tellingly though, she adds: “When I interviewed Jimi, we spoke about blues. He appreciated my deep connection.”

Wilmer’s break into journalism, fuelled by an early and snowballing passion for African American music, had happened at the age of 17. “Woe betide any American musician whose address was printed in a magazine,” she says, “as I would write to them! I wrote to Jesse Fuller and he replied so I started up a correspondence and wrote my first piece from what he told me.”

It was published in Jazz Journal and soon Wilmerwas working for other titles and meeting leading African American musicians regularly. “For the most part,” she says, “everyone I met was lovely and encouraging. Sister Rosetta Tharpe gave me a pair of her earrings – no, two pairs! She was just the warmest, nicest person.”

Others were less charming. Fela Kuti, whom Wilmer got to know while living in Nigeria for six weeks, was particularly bad-tempered. “And always walking around in his underpants,” she says. “Who wears underpants among other people? He was somewhat autocratic. Not very likable.”

Miles Davis, too, wasn’t exactly endearing. She remembers approaching the jazz great for an interview after photographing a gig, only for him to decline in a gruff voice. “His female partner said, ‘Go on, talk to the girl.’ And he replied, ‘I might have if she’d lifted up her skirt.’ Very Miles.”

Blues, jazz and gospel inspired Wilmer throughout her life. At 81, she continues to cut a formidable figure and this has been a busy year. She has a new photobook out, Deep Blues: a striking collection showing African American blues musicians and their communities. It accompanies the exhibition Blue Moments, Black Sounds, which recently opened at the Worldly Wicked & Wise gallery in London. “Just in time to earn me some money to pay my winter fuel bills!” she says.

Wilmer has long been a leading voice – and lens – on the subjects of music, race, women’s rights, minority communities and cultural ferment. Today, though, she no longer takes photographs – “I got tired of lugging all that gear around” – but still regularly contributes to Jazzwise magazine. Born in Yorkshire in 1941, she was raised in London by her mother after her father died when she was six. Wilmer was barely a teenager when she took her first portrait of a performer, on her mother’s Box Brownie in 1956.

“We’d been to see Louis Armstrong at Earls Court,” recalls Wilmer, who still lives in London. “I’d connected with jazz strongly and my mother graciously encouraged my enthusiasms. So when I learned what airport he was flying out of, I requested we be there. And there he was! I asked Louis if I could take his photo – and that was me started.”

In 1964, the London-based magazine Flamingo sent her to the Gambia, Nigeria, Liberia and Sierra Leone for six weeks where she covered all manner of subjects. “It later turned out that Flamingo – which was widely distributed in the US, the Caribbean and west Africa – was funded by MI6,” says Wilmer, before hastily adding: “Not that the work I did for them had any kind of agenda.”

If Wilmer ever had an agenda it was that of documenting Black musicians at work and play. Whether showing them as they performed, or relaxed backstage playing poker as she captured Muddy Waters doing, her photographs are beautifully composed yet very naturalistic. She avoids posing her subjects, preferring to let their personalities shine through.

“Of all the musicians I photographed,” she says, “the nicest was BB King. “Once, in New York, he invited me and a friend to jump on his bus as he was off to play out of town. When we got back late that night, BB insisted on us joining him at home for dinner – he woke one of his daughters and asked her to fry some chicken! Then he offered us the cab fare. I said, ‘B, you’ve done so much for us – no more!’ He was kind, intelligent, generous – an exemplary musician and human being.”

Jazz People, Wilmer’s first book, was published in 1970 and, a year later, she was approached by the V&A about an exhibition. Deciding she needed stronger images, Wilmer took off for the deep south, then stayed in New York with Ornette Coleman for five weeks. The result was the 1973 show Jazz Seen: The Face of Black Music. Earlier this year, the museum marked the show’s 50th anniversary by including a Wilmer image – of American gospel singers Inez Andrews and Elaine Davis – in its exhibition Energy: Sparks from the Collection.

Back then, the music Wilmer championed was often seen as niche. In 1977, her book As Serious As Your Life was the first to document America’s burgeoning free jazz scene and, in particular, the efforts of Afrofuturist and cosmic adventurer Sun Ra, whom Wilmer knew well.

“Sun Ra had this almost cultlike thing going on,” she says. “He had all these young male musicians living with him and obeying what he said. It was an odd situation but he himself was quite warm and approachable. He certainly had a sense of showmanship – if he ever saw me holding a camera, he’d put on one of his sparkly hats. He always wanted to look the part.”

Nowadays, the late maverick is a hipster icon, whose band the Arkestra draws large, youthful audiences. “I’m surprised by the enthusiasm now surrounding his music but jazz is so different these days – at least in the way people appreciate it.”

Wilmer, a lesbian feminist, embraced activism throughout the 1970s and 80s. In 1983, she co-founded Format, an all-female photographic agency, with Maggie Murray. Its campaigning photography is currently being honoured in London at the Barbican’s Re/Sisters exhibition and Tate Britain’s Women in Revolt! show. But protest eventually wore Wilmer down. “I got tired of being pushed around by the police – and other people,” she says.

The Blue Moments, Black Sounds show includes more than 50 photos of musicians and their communities. They arguably rank among the finest photos of musicians ever taken, and Wilmer is rightly proud of both them and the connections she built. “John Coltrane was such a gentle, humble man,” she says of the saxophonist.

Sadly, though, Miles Davis was not the only musician whose dark side Wilmer saw. Her 1989 autobiography Mama Said There’d Be Days Like This describes her many struggles, including an attempted sexual assault by a famous jazz trumpeter backstage. That incident ended with Wilmer knocking him out, but today she declines to discuss the incident and his photo doesn’t appear in any of her current exhibitions.

“I encountered so many wonderful people,” she says, “that I can happily ignore those who tested me.”

• Deep Blues is published by Café Royal Books. Blue Moments, Black Sounds is at Worldly Wicked & Wise, London, until 30 November.

During the late 1990s and early 2000s, an unexpected hideaway for big-name celebrities existed beneath the Marc Jacobs store in New York City. Inside the original flagship on Mercer Street, past the dressing rooms and racks of clothing, into the back of the shop and down the stairs to the basement, the vice president of public relations for Marc Jacobs’ store at the time, Robert Rich, had a windowless office that doubled as a safe space for his famous friends—Winona Ryder, Sofia Coppola, Kate Moss, and Grace Jones among them.

“It was kind of like my clubhouse,” Rich tells me on a recent afternoon from his home in Manhattan. “Nobody could see us. It might be pandemonium outside with paparazzi in the street, but we would all be alright downstairs in the office.” In that basement, Rich spent countless hours photographing the stars that would come in and out of his workspace for fittings (or simply to hang out) with a Polaroid camera. And there, he cultivated what he describes as an “instant trust” and decades-long friendship with Ryder specifically, with whom he became quite close over the years. Standing in front of the infamous “mood board” wall of Rich’s office—where he would tape up pictures he’d ripped out of magazines for inspiration—Ryder felt free to pose with silly abandon, wearing wacky get-ups or making funny faces for the camera.

Now, a collection of those intimate photographs of Ryder will be published in a hardcover book, titled Winona, from the publisher IDEA. The book contains over 100 images of Ryder in Rich’s basement office—but also includes paparazzi photographs of the duo shopping in SoHo or grabbing lunch, straight from the pages of Star magazine and The New York Post. (Rich is described in these articles as a “mystery man.”) There are images from their more glam nights out, like when Rich and Ryder attended the 2009 Met Gala together. “Marc was hosting with Kate Moss, Selma Blair was there, Anne Hathaway was there, Madonna was with Marc because she’d just done the LV ads,” Rich recalls. “And Marc’s table was full of Brazilians.”

And of course, there are a multitude of images from their time spent together as BFFs. “We went to the movies together, we had sleepovers,” Rich says, pointing to photos of Ryder he shot on his bathroom floor. “I was in L.A. a lot and she was in New York a lot, so when I was out there I would see her, and vice versa. And it was so funny, because every time I’d see her, she’d be doing a different movie and I never could recognize her immediately. She was always completely different—with blonde hair, long hair, short hair. It would take me five seconds to realize—oh my god, it’s Winona.”

The two worked hand-in-hand on the book. “I let her take out whatever she wanted or whatever she didn’t like,” Rich says. But when he came to the decision that he’d publish the 20-or-so-years’ worth of photographs in a tome, there were a few pictures he knew he had to include. “The day that we hung out with Kate Moss in my office with Patricia Taylor, Keanu Reeves’s mother—she’s a good friend of mine,” he says. “It was just a fun day. Even Marc stopped by to say hi. Kate was cutting dresses up on Winona’s body; we had long dresses, she’d make ‘em into mini dresses.” Rich believes that was the first time Ryder and Moss met: “I think they saw each other once at a party or something, but it was the first time they talked and hung out,” he recalls. “I always thought they could be friends. It was a great place for them to meet with no one around. And they hit it off.”

But the pictures of Ryder at her most vulnerable do not feature her face at all. There are a group of images that feature her bare midsection, her breasts covered by her hands. They look like they were shot on a flip phone camera, exuding a level of intimacy you just won’t see in professional or editorial shots. Here, though, Rich’s memory gets a bit foggy: “I don’t think there’s a story behind those pictures,” he says. “Maybe we were getting ready because she did the ‘Protect the Skin You’re In’ t-shirt? Maybe we were prepping for that… Because she never took her clothes off before for a photographer. But she did it for Marc—and Robert Rich!”