The Supremes - Mary Wilson, Diana Ross and Cindy Birdsong - in 1968. Photo / file
With make-up applied, wig in place and hip-shaking figure cosseted inside a soul-queen frock, it's difficult to believe Mary Wilson is a 75-year-old grandmother.
The singer, standing in a television studio in west London, is about to go live on Good Morning America, where she will be unveiled as a contestant on Dancing with the Stars (the US version of Strictly Come Dancing).
"My daughter Turkessa, my son Pedrico and my 11 grandchildren are so thrilled that I'm in Dancing with the Stars," she tells the perma-tanned hosts. "Finally, Grandma is cool!"Laughter from the studio audience in America filters down the line - the joke being, of course, that Wilson was cool decades before her first child was even born.
As a founding member of The Supremes, Wilson dominated the charts on both sides of the Atlantic between 1964 and 1970 with hits such as Where Did Our Love Go?, Baby Love, Stop! In The Name of Love, You Can't Hurry Love and You Keep Me Hangin' On. In the annals of pop, The Supremes are one of the most successful girl groups of all time.
But Wilson didn't make much money during that period. When Diana Ross left the group in 1970 and Wilson took over the accounts, she discovered she had just $100,000 to show for the hits. Motown had been their lawyers and their managers, and the founding members - Wilson and Florence Ballard - had just been young girls with no experience of business.
Not that Wilson harbours any ill will towards Motown. The singer features in a new documentary about the record label, Hitsville: The Making of Motown. She also talks fondly about the hit factory in a new book, Supreme Glamour, a sumptuous coffee-table tome that tells the story of The Supremes: how 17-year-old girls in home-made brown shifts (their band was then called The Primettes) ended up as pop queens, clad in dazzling haute couture, by the end of the 1960s.
"We'd go in to record a song, then we'd have to go into different classes. And [Maxine] Powell [Motown's resident stylist] would say: 'You ladies are just diamonds in the rough, and we're here to polish you.' Woah, that was kinda interesting, right?" Wilson remarks, lips pursing, eyebrows shooting to the ceiling of the meeting room in which we're sitting."
And then we had Mr Cholly Atkins, our choreographer. He taught us all the hand movements.
Then, Maurice King, he was really wonderful. You know how Gladys Knight and the Pips and The Temptations and us always had monologues? Maurice, who was [also] the band leader, would write out these really eloquent passages for us to say in the middle of the songs."
Motown, then, invested in the best of the best? Wilson nods.
"Artist development was comprised of all of these different lessons from people who were former performers. We learnt from real professionals, who'd been out there working for years, on the Chitlin Circuit we called it, the black [nightclub] market."
The result was a global culture-quake. Of course, as biographies have revealed over the years, the polish concealed deep fissures.As the group became successful, Ross fought to establish herself as the lead singer and force Wilson and Ballard into the background. She began an affair with Motown founder Berry Gordy and would double-cross her bandmates by slipping into a different dress from theirs at the last minute, to set herself apart on stage.
Another alleged ruse was to stretch out her hands when they were live on TV to obscure Ballard and Wilson's faces.
(One has to wonder whether it is coincidence that, on the cover of Wilson's new book, Wilson and Ballard's faces are clearly visible and it is Ross who is looking down, her face obscured by her hair.)
"We did lose our lustre," is all Wilson will say about this feud now. "We're always sisters. But we're not friends in terms of picking [up the phone] and saying: 'Girl, guess what's happening today?' We're like distant cousins who don't see each other."She has more than made up for her paltry takings in the first five years of The Supremes - she now prefers to focus on the positives.
"We created history."
The actress Whoopi Goldberg, in her foreword to Supreme Glamour, recalls how The Supremes "made [her] head explode" when they found success.
"[A]ll those gowns, all those pantsuits, all those caps, gloves, furs, the make-up, the eyelashes, the wigs... made me believe they were talking to me. I too could be well-spoken, tall, majestic, an emissary of black folks, who also came from the projects... I look back and wonder if they had any idea that they taught me and a new generation the pride of being black."
I ask Wilson: did you have any idea?
"No! We were just being ourselves, using the gifts that God gave us. We were just enjoying ourselves. I can't speak for Florence and Diane, but as I got a little older, I realised, 'Yeah, we did touch other lives'. And not just women. Men, too."
Wilson herself touched the lives of two very famous men: Tom Jones, with whom she had an affair (the two would fly all over the world to meet each other); and Steve McQueen, whom she met at a party hosted by Motown's publicity director, Bob Jones, and dated for four months. She also knew Michael Jackson very well, as a fellow Motown artist.
Was she surprised by the allegations of child abuse made in this year's film, Leaving Neverland?
"I was surprised, sure," she says. "Because that's not what I knew. It's like anybody else - you don't know what they do in their bedroom. But I had no idea, and would never have thought that. I'm sorry if that was true. Really sorry.
"But he was a great young man. My adopted son and he were very close, and Diane's brother, Chico, because they were the same age. They'd go out and play together, just like any other little kids. In fact when I saw him at the World Music Awards he came up and asked: 'Mary, how is Willie?"' she says, impersonating Jackson's helium-high whisper. "That's what I remember."
Wilson's involvement with Dancing with the Stars turns out to be brief; she is the first contestant to be eliminated (leaving behind Christie Brinkley, Dawson's Creek actor James Van Der Beek, and, improbably, former White House press secretary Sean Spicer, among others). But one suspects her 100-watt radiance will not be dimmed."How did three little black teenage girls from Detroit, Michigan, become the most beloved and biggest-selling female singing music trio in music history?" she asks at the beginning of Supreme Glamour. "It came down to one mutual thing that we had in our hearts: we dared to dream."
Andy Serkis is the man behind Gollum and will step into the role of director for the film.