The recent death of Prince sparked a revelation for director Amy Berg, who just spent eight years immersed in the life of another musical legend, Janis Joplin, culminating in the feature documentary “Janis: Little Girl Blue” which she also wrote and produced along with Alex Gibney, Jeff Jampol and Katherine LeBlond.

Flash back to the fall of 1970. Less than three weeks after Jimi Hendrix died, the world mourned another drug overdose death of a larger-than-life musician, the 27-year-old Joplin, whose career had burnt white-hot for the four previous years before her tragic, untimely passing.

“You do see a lot of similarity in the intensity of performances with Prince and Janis,” said Berg, whose documentary is set to air as part of the “American Masters” 30th anniversary season on PBS. “I’ve been watching a lot of Prince, but they both put so much into their shows it became who they were in life as well. For Janis, it was about becoming a caricature of herself and not being able to set boundaries and turn off being the performer.”

Berg began working with the Joplin estate in 2007 — the singer’s siblings Laura and Michael are interviewed in the film — dealing with rights issues, financing, finding previously unseen footage and culling video from Joplin’s iconic performances at the Monterey Pop Festival and at Woodstock.

Among its most gripping elements are the letters Joplin wrote to family, friends and lovers, which are read by Chan Marshall, an indie rocker better known as Cat Power. While many had been previously published, others are revealed for the first time and often expose Joplin’s naivety, fears and sadness. Most of the correspondence was saved by Joplin’s mother.

“The letters were always part of how I wanted to tell the story,” Berg said in a phone interview from New York. ”They showed a side of Janis not seen in public. They really shaped the narrative of the film and brought a new depth to it. And then there’s the bonus of Cat invoking the perfect intonation.”

Over the past few decades, there have been many attempts to capture Joplin’s story on film, with some of Hollywood’s biggest names attached. None have yet reached fruition.

“I think that Janis has a larger-than-life story. It’s a complex story. And to make it interesting, I think you really have to get into her,” said Laura Joplin during a winter TCA presentation about the documentary. “And I’m eager to see someone come forth and be able to give us the kind of Janis that Amy [Berg] gave us, the real person with the complexity, the drama of the music, and the real soulful sense and the humor. There’s a lot there. And we, as a culture, you know, we’re kind of hung up on the simple image. And I think to do a good movie, you’re challenging someone to find the depth.”

For her part, Berg said that as a woman, she felt compelled to tell Joplin’s story because her legacy had become more about how she died — joining the infamous “27 Club,” which includes Hendrix, Jim Morrison, Amy Winehouse and Kurt Cobain — than how she lived.

“And when I look at what she’s done for women, for women in music, and for me as a woman, I felt kind of a responsibility to show her life,” Berg said during TCA. “And she left such a strong amount of impact on the music scene, and she was such a soulful, intelligent, beautiful person. So, for me, it was very important to not focus on the worst part of her life, but the best part of her life.”

“Janis: Little Girl Blue” was released theatrically late last year and comes 45 years after the release of “Pearl,” Joplin’s final studio album, which came out posthumously in January 1971. In the film, Power performs a song from the album called “A Woman Left Lonely.”

The documentary paints a portrait of a complicated, often vulnerable and insecure yet driven talent who always stood out in her hometown of Port Arthur, Texas, and was harassed in high school for being different — and a rebel, a quality that later came to define her as one of the few female superstars in the vaunted rock ‘n’ roll era of the late 1960s.

In addition to insights from Laura and Michael Joplin, there are interviews with people in her life at the time — notably Clive Davis, Kris Kristofferson, Dick Cavett and D.A. Pennebaker, and those she inspired musically and artistically, including Melissa Etheridge, Pink and Juliette Lewis. The “American Masters” version includes additional interviews with the latter three artists.

Also revealing are interviews with members of Joplin’s former backup band, Big Brother and the Holding Company, including its drummer, Dave Getz, who marvels at some previously unreleased footage of Joplin in the studio shot by the legendary Pennebaker. He talks about the music they performed, a melding of the blues, folk, jazz and rock, with Joplin’s bravado stage presence always the centerpiece.

“She made such a strong impact on so many different people, especially the Big Brother guys — it taught me the most about her,” said Berg. “It’s been 45 years and she still has such a huge influence. Their memories of her are still so close to the surface.”

Laura Joplin, who wrote the 2005 book “Love, Janis” about her sister, said she’s excited to bring “Little Girl Blue” to audiences. “I want them to have the same experience I had in enjoying being in Janis’s company,” she said in an email interview. “Janis excited me when she shared her thinking. She was well-read and well-spoken and always added new elements to a discussion so that I learned something. Janis was also entertaining, a great storyteller and an engaging listener. I feel that these qualities are in the documentary and I’m glad people get to spend some time with the sister I enjoyed and loved.”

“I’m thrilled that Janis Joplin is taking her rightful place in the series alongside other music icons of the era like Jimi Hendrix and the Doors,” said Michael Kantor, executive producer of “American Masters,” in a statement about the doc. “I hope viewers enjoy Amy’s extended cut, made exclusively for our broadcast.”

(“Janis: Little Girl Blue” premieres Tuesday, May 3, at 8 p.m. ET on PBS.)