PBS’ American Masters documentary “How It Feels to Be Free” – which counts Alicia Keys among its roster of exec producers – salutes the careers of six Black female entertainers who used their celebrity to promote civil rights and challenge racists stereotypes.

The documentary – which premieres today on PBS and is set to become a market priority for its distributor Fremantle at NATPE this week – is directed by Yoruba Richen (“The Green Book: Guide to Freedom,” “The New Black”).

A Yap Films production in association with ITVS, Chicken & Egg pictures and Documentary Channel in Canada, it celebrates the careers of Lena Horne, Abbey Lincoln, Nina Simone, Diahann Carroll, Cicely Tyson and Pam Grier.

While its premiere may seem timely in the wake of the Time’s Up and Black Lives Matters movements, PBS and ITVS first came on board five years ago – it just took years to raise the necessary finance, according to Richen.

It was only when two of the film’s executive producers – filmmakers Lacey Schwartz Delgado (“Little White Lie”) and Mehret Mandefro (“Sweetness in the Belly”) – met Yap Film’s chief creative officer Elizabeth Trojian at American Film Showcase that the project was able to go into production.

Keys was also an early supporter of the film and the singer-songwriter features in the doc, alongside other luminaries inspired by these women – including Halle Berry, Lena Waithe, Meagan Good, LaTanya Richardson Jackson and Samuel L. Jackson.

Commentators also include author and academic Ruth Feldstein (whose 2014-published book of the same title inspired the film) as well as Horne’s daughter Gail Lumet Buckley.

Among the abundant archive content included in the doc are stars’ meetings with key civil rights figures, including footage of actress and singer Lena Horne at an NAACP rally with Medgar Evers in Jackson, Mississippi the weekend before his assassination.

While audiences will be familiar with these entertainers, many will be unaware of their political activism and the female civil rights activists they met. Richen believes this is because Black women’s stories have been under-told until now.

“We hear about Malcolm and Martin but never Fannie Lou Hamer or Ella Baker or Diane Nash who were the backbone of the civil rights movement,” she says.

The director admits that there were elements of these entertainers’ careers that surprised her – including Abbey Lincoln’s evolution from jazz chanteuse to civil rights activist.

“I was more aware of Nina Simone’s activism, but Abbey’s… she came first and blazed a trail with the political significance of her songs and the transition of her style to a more Afro-centric Black woman,” she says.

The affirmation of Black women’s beauty by Simon, Lincoln and Tyson is an issue Richen said she was keen to explore more in her film.

“We see how women are taken more or less seriously based on their physicality,” says Richen.

“There is the more conventionally glamorous Carroll who admits she got many of the roles because she looks a certain way. The film is having that conversation but also pointing out things like Cicely Tyson’s embracing of natural Black hairstyles,” she adds.

The documentary reveals how this issue dates back to the golden era of Hollywood when Horne was regarded as “too pale” for some “Black” roles, but “too Black” for others, Richen says.

The film legend was famously passed over for the romantic lead in “Showboat” – which required a light skinned Black woman – in favor of Ava Gardner.

“We really wanted to show that this was an on-going issue that has been around since the early days of the entertainment industry,” says Richen.

Richen also leaves room in the narrative to explore the differing opinions among Black female entertainers about how they should be represented on screen.

Actress Cicely Tyson, who was very particular about the roles she took on over her seven-decade career, was critical of the Blaxploitation films from the Seventies that provided a lot of Black actors with work.

Tyson feared that the global popularity of this genre could lead to a skewed worldview of the way white audiences viewed people of color.

Yet others point out how Pam Grier, another subject of the film (although not one featured in Feldstein’s original book), remained for a long time one of the few women of color to play an action lead in a string of films, most notably “Coffy” and “Foxy Brown.”

As “Master of None” actress and U.S. screenwriter Lena Waithe comments in the doc: “If that’s what Blaxploitation brings us, then I’ll take it.”

Richen also argues that the roles these entertainers selected is also more politically astute than audiences may realize.

Horne had it written into her contract that she would never play a maid, while Diahann Carroll speaks on camera about how she always viewed her career as a pioneering one that introduced Black women to stage and screen, especially the small screen through her roles in Sixties sitcom “Julia” and the character of Dominique Deveraux in “Dynasty.”

Richen doesn’t shy away from examining the limitations these entertainers experienced: Lincoln’s career suffered for her activism while Tyson’s price for being selective about the roles she took on meant that she often had to wait years for the right part to come along.

Horne, who was blacklisted for her activism in the Fifties, played the female lead in just two films: “Cabin in the Sky” and “Stormy Weather.” Elsewhere her career was limited to singing-only roles.

These sentiments are echoed decades later by Halle Berry’s segment in the documentary, in which the star reveals she has worked far less since winning her Academy Award 12 years ago, due to a paucity of decent roles that have come her way.

So what does Richen think the industry can learn from the experiences of these women and how can it ensure that roles for women of color are plentiful, frequent and not playing to stereotype?

“Diahann Carroll says it in the film,” says Richen “It’s about getting behind the camera and to have the power to green light.

“We need to have women of color at the heads of these studios and the funding opportunities for this to happen and for us to get our stories made in a way that tells the truth about our experience.”