How do you capture the essence of reggae legend Bob Marley?

For starters, you have his son Ziggy Marley, a producer of the new biopic “Bob Marley: One Love” (in theaters on Valentine's Day), standing by to steer you right.

“There was one scene where Kingsley (Ben-Adir, who plays Bob Marley) was walking up some stairs,” says Marley, 55, himself a reggae star. “And I said, ‘Bob always took two steps at a time, not one!’"

Two steps at a time sums up the productive pace of Marley’s life between 1976 and 1978, a period captured in “One Love” through kinetic performances by Ben-Adir (“One Night In Miami”) and Lashana Lynch (“The Woman King”) as Marley’s wife, Rita.

Ben-Adir says spending time with the Marley family was the only way to humanize the myth: "Whatever idea I had of Bob before, I realized quickly that I didn't know anything at all."

Marley's legend took hold in those two years, a period when he released some of his greatest albums (including “Exodus” and “Kaya”), was nearly killed by gang members (but still performed in concert days later), and got leaders of Jamaica’s opposing political parties to clasp hands (at the aptly named One Love Peace Concert).

For Kingsley Ben-Adir, capturing Bob Marley meant studying his interviews while filming 'Barbie'

The challenges of becoming Marley were twofold: learning Marley’s particular version of Jamaican patois, and capturing his mannerisms and movements.

For the former, Ben-Adir leaned heavily on a trove of Marley interviews. He would write out Marley's words and ultimately relied not only on Jamaicans on the set but also on language experts to help him with the lines phonetically.

“I spent all my free time on the ‘Barbie’ set (where Ben-Adir played one of the Kens) prepping for this movie,” he says.

To capture Marley’s distinctive mannerisms, from his smile to his head tilt to his trance-like dance moves, Ben-Adir enlisted the help of Polly Bennett, who helped Austin Butler become Elvis.

“Polly looks for the psychology of how someone moves, so for Bob, it was about looking at how I moved, and her going, ‘No, don’t move your arm that way because Bob never would,’ ” he says.

Ben-Adir has one regret: After working hard to perform the song “Lively Up Yourself” (from a legendary concert stretch at London’s Rainbow Theatre in 1977), it was cut from the film for pacing reasons. “I spent more time on that than anything,” he says. Ziggy Marley says to look for it in the outtakes.

One thing Ben-Adir couldn't control is being, at 6-foot-2, some 7 inches taller than Marley. "That's OK," says Ziggy with a smile. "In my memory, Bob was a giant. So we're representing him in art as larger than life."

'One Love' recreated Bob Marley's Kingston home and captured his epic soccer scrimmages with bandmates

The Marley family was adamant: The biopic couldn't truck in cliches. So the challenge was figuring out how to convey the essence of a spiritual man who used music to preach love for one another and his Rastafari movement, says director Reinaldo Marcus Green (“King Richard”).

"You don’t mess with Bob and his legacy,” says Green. “So we had to carefully figure out what parts of his life really captured his full humanity. And for that, we needed the family.”

That included not only Ziggy but sibling Cedella Marley, 56, and reclusive matriarch Rita, 77, as well as offspring of former band members – who play their parents in recording session scenes − and countless friends.

Great attention was paid to keeping the settings real. Filming took place in London, where Marley spent those critical years, and Jamaica. Set designers recreated locations with specificity, ranging from London’s Basing Street Studios to Marley’s home at 56 Hope Road in Kingston.

“I went into the set, which was down the street from the real place (now a Marley museum), and it was incredible, the details,” says Ziggy Marley. “Me and my brothers and sisters went in there, and it just brought back so many memories of running around that house as kids.”

There was even great care taken to re-create high-level pick-up soccer games, a lifelong passion for Marley. Gifted players were drafted to make those scenes feel genuine, and Ben-Adir pulled off some deft moves.

“I told Reinaldo, if we don’t get the soccer scenes right, we can’t make the movie,” Ziggy says with a laugh. “My father would be very upset if that wasn’t done right. Football (soccer) was so important to him.”

Lashana Lynch set aside her notebook when meeting with Rita Marley: 'She has a presence'

To embody Rita Marley, Lynch spent time with her in Jamaica. But that interaction was less about pulling details from her tumultuous life with Marley than just “taking in her essence, she has a presence,” says Lynch.

The biggest insight for the cast was understanding that Bob Marley’s devotion to the Rastafari movement, a Jamaican religion anchored to the Bible and focused on the god Jah, came directly from Rita.

“She brought that to Bob, and he brought it to the world,” Lynch says. “I’m of Jamaican heritage and it was very important for me to uphold my culture. So although I brought my notebook when I met with Rita, I mostly left it in my bag and just tried to soak up her raw, clean, balanced energy.”

Lynch did pick up one mannerism from Marley: “She holds her hands out in this sort of dainty way, and I wound up doing that all the time, on set and off. It was with me all the time."

So did all the work on patois, music and mannerisms pay off?

Ziggy Marley just nods. “For me, when I see this movie, I see my father,” he says.

But the ultimate compliment came last month in Kingston, which hosted the movie's world premiere for family, friends and even Prince Harry and Meghan, the Duchess of Sussex.

“Everyone told me afterward that they liked it,” says Marley. “And I would hear it, believe me, if they didn't. When it comes to Bob, Jamaicans don’t play.”

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