She is still celebrated as the queen of rock’n’roll but, one year after Tina Turner’s death aged 83, the barnstorming singer’s legacy includes a “fierce transparency” about her trauma, said the writer of the bio-musical Tina.

Katori Hall met Turner many times at the star’s home while writing the book for the musical, which opened in 2018 and has become the longest-running show ever at the Aldwych theatre in London.

“I probably am much more honest than I would have been had I not met with her,” said Hall, who described Turner as being fully open about her life from their first encounter. The show recounts traumatic episodes such as serial abuse from her first husband, Ike Turner, and the racism and ageism that the singer experienced within the music business.

“There is a burden that comes with being so honest and for being a truth-teller and a trailblazer, and I was really grateful for her vulnerability, more so than her toughness,” said Hall. “There’s great power in vulnerability. I always use this phrase ‘fierce transparency’ in all of my relationships, whether it is my personal relationships, a romantic relationship, a business relationship. I’m fiercely transparent with all parties involved and I think it has a lot to do with the fact that I got a chance to dance with Tina at the end of her life.”

Hall said that Turner had found it painful to remember some of the events and relationships depicted in the musical, including the way her mother “still didn’t quite give her her due, even when she was an icon and had won her Grammy and became the Tina Turner. I could tell that there was a lot of hurt.”

The writer found herself “zeroing in” on the moments when Turner was considering how to answer a question. “I often listened to her silence … I noticed that she was really trying to find the language to talk about her mother.” Hall felt it was important, in the musical, to draw a connection between Ike Turner’s abuse and Tina’s difficult childhood because when women are “caught in a cycle of domestic violence and abuse, it can be connected to earlier life experiences”.

After Turner died, Lenore E Walker, director of the US-based Domestic Violence Institute, said that the singer’s decision in 1981 to tell People magazine about her experiences of abuse brought greater awareness to the problem. “Women were not believed when they spoke out about domestic violence, so when Tina Turner, a well-respected and famous singer, spoke out, it gave other women the courage to do so, also,” she told the BBC.

Hall had listened to Turner’s music since childhood – her mother was such a big fan that she named one of Hall’s sisters Tina. Hall likens the image of Turner in the 1984 video for What’s Love Got to Do With It, which she watched as a child, to a “superwoman” at a time when images of black women were “just extraordinarily rare on TV, especially black women who had so much kind of braggadocio about themselves”.

The writer is currently directing the new series of her TV show P-Valley, set in a strip club, and in the summer her Pulitzer prize-winning comedy The Hot Wing King will have its UK premiere at the National Theatre directed by Roy Alexander Weise.

From next month, Karis Anderson and Zoe Birkett will share the role of Tina in the West End production’s new cast. The musical, directed by Phyllida Lloyd and featuring Turner’s greatest hits including a roof-raising finale medley, is a chance for fans to still have a sense of the star’s presence, a year after her death, said Hall. There are versions currently on tour in Australia and North America, as well as a production in Stuttgart, plus a UK and Ireland tour set for next year. It is like “one last concert” said Hall – “and it’s happening all around the world”.