The research only took them so far, so they decided to come and see Hitsville, U.S.A., for themselves.
Brandon Victor Dixon, who portrays the label's founder, Berry Gordy, and Valisia LeKae, who plays its signature songstress, Diana Ross, visited the Motown Museum on Tuesday, taking a lengthy tour of the two-level home that produced the soundtrack of a generation.
"I'm trying not to get emotional," LeKae said as she methodically inspected the hundreds of mementos - posters, gold records, clothing and more - on display at the Motown Museum.
LeKae, a Broadway veteran who has appeared in "The Book of Mormon" and "Ragtime" among others, worried about losing her composure when it came time to visit Studio A, the famed space in which Gordy and his army of artists, writers, producers and engineers signed, sealed and delivered hit after hit throughout the 1960s.
And she succeeded, descending a small flight of stairs into the square, smallish room and calmly checking out the famed studio affectionately called the "Snake Pit." LeKae marveled at an oversized black-and-white snapshot on the wall of Ross singing with a smiling Gordy looking on.
It wasn't until later, while visiting the home's upstairs, that LeKae's emotions kicked in.
Standing underneath the "echo chamber," a hole cut in the upper level's ceiling designed to create unique sounds for the recording process, LeKae belted out the first few lines of the Supremes' "Where Did Our Love Go."
"Baby, baby / Baby, don't leave me," she wailed, before the tears began to well up and she had to stop singing.
"This is, like, amazing," she said.
LeKae and Dixon, who earned a Tony nomination for his work in "The Color Purple" and bears more than a passing resemblance to a Motown-era Gordy, will be front and center when the show debuts this spring.
"Motown: The Musical" begins its run of preview performances March 11 ahead of the official opening on April 14 at New York's Lunt-Fontanne Theatre.
That gives Dixon, LeKae, Gordy (who's producing and writing the book) and director Charles Randolph-Wright four months to bring the show to the stage.
To that end, Randolph-Wright also was at Hitsville on Tuesday, seeing prospective actors during a callback session in Studio A. He's still looking for understudies and others to play smaller parts.
It wasn't Randolph-Wright's first visit to Motown's birthplace as it was for his two leads, but for the 56-year-old who proclaims that "Motown's in my DNA," it was no less special.
"What a joy to be a part of (the Motown) movement and what a responsibility to try and place that in the world," Randolph-Wright said, sitting on a piano bench in Studio A. "So, I've been very careful about trying to do that the right way."
And he has, working for the past three years on "Motown: The Musical," holding a nationwide casting call and working with Gordy and the other producers to identify which of the overwhelming number of songs from the Motown catalog to include on stage.
"The show is 15 hours," Randolph-Wright joked.
The first version had 100 songs in it, he said, and "I wanted every song."
While he said the show's decision-makers are still deliberating about which songs make the final cut, one thing is certain about the musical selections: A few numbers in the show will be Gordy originals, written specifically for it.
"It's so interesting to see him go back to being a songwriter after all these years," said Randolph-Wright, who described one Gordy-penned song as having "all the textures of what Motown is and was, but it's new."
As for the man playing the man, Dixon spent his Tuesday walking through the halls of the Motown Museum, taking in every word tour guide Eric Harp and the other docents offered and, as he put it, "soaking it all in."
At one point, he kneeled down and softly touched the cushion of a red-orange couch upstairs on which Marvin Gaye would take the occasional slumber.
Dixon burst out laughing, then leaped up and continued the tour.
Asked what was so funny, he quickly responded: "Because Marvin Gaye slept on this couch!"
All three of the Hitsville visitors spoke of their great respect and admiration for Gordy and the history of Motown and how important they felt it was to do it justice on stage.
"There's an energy here that is palpable still," Randolph-Wright said. "And it remains in this space. I think more than anything, the second I walked in here, it told me that I have to be honest" in telling the Motown story.
The first time he visited the museum, Randolph-Wright remembered walking into the gift shop, where he "bought everything," including a Temptations T-shirt that read: "Live It Again."
"I love that, because that's what we're doing," he said.