From left, singers Judith Hill, Merry Clayton, Darlene Love, Tata Vega and Lisa Fischer from the film “20 Feet from Stardom” at the 2013 Sundance Film Festival in Park City, Utah. (Victoria Will/Invision/AP)

You’ve seen them but not noticed them. You’ve heard them but not listened to them. The new documentary “20 Feet From Stardom” shines a spotlight away from center stage, on the world of female backup singers.

Directed by Morgan Neville, the film looks most specifically at the lives and careers of six women — Darlene Love, Merry Clayton, Lisa Fischer, Tata Vega, Claudia Lennear and Judith Hill — whose careers span generations of music and who have worked with a broad spectrum of artists, including the Rolling Stones, Michael Jackson, Phil Spector, Stevie Wonder, Sting, and Ike and Tina Turner.

“20 Feet” premiered on the opening night of the Sundance Film Festival, as did last year’s “Searching for Sugar Man,” a tale of music trumping obscurity that went on to win the Oscar for documentary feature.

Audiences have burst into applause during showings of “20 Feet From Stardom,” moved by the excitement of the music and the emotions of the story.

The movie has also helped to push its subjects further into the spotlight. Hill, recently a contestant on “The Voice,” performed a song from the documentary film on NBC’s “The Tonight Show.” Love was interviewed for the first time on CBS’s “Late Show” after singing there for many years. A “Best of Merry Clayton” album is being released. Lennear is looking to get a new band together.

“To make a film about a group of people that maybe didn’t have the opportunities and catch every break they should have, and then have that film provide those opportunities is something I could never have allowed myself to imagine happening,” Neville said. “But it is actually happening, and that’s the biggest reward.”

The film was the idea of Gil Friesen, former president of A&M Records and executive producer of such films as “The Breakfast Club” and “Better Off Dead.” While at a Leonard Cohen show, he was struck by the background singers and realized that their world had never been explored.

Having never produced a documentary before, Friesen went to Neville, a longtime director and producer of such music-related documentaries as the Carole King-James Taylor film “Troubadours” and the Rolling Stones documentary “Crossfire Hurricane.”

Friesen had an idea and a title.

“When I said, ‘Backup singers are interesting, but what’s the film going to be?’ he said, ‘I have no idea; that’s your job.’ It was really unchartered territory,” Neville said of their initial conversation.

Neville and Friesen interviewed dozens of background singers as they shaped the story. From there, Neville wrote up a treatment of what he thought the rest of the film could be. Although he was initially concerned the film would be a downbeat look at his subjects, Neville found something more in their perseverance.

“The breakthrough to me was that the film is not about trying to go solo and trying to achieve your dreams and not making it,” Neville said. “It’s about the third act of the film, what happens when you don’t achieve your dreams and how the measure of a person is how they dealt with that. That’s the deeper thing to me.”

Neville said that Lennear was perhaps the most difficult subject for him to find. She had enjoyed relative fame as a member of the Ikettes, with Ike and Tina Turner, and later released a solo album in 1973 and appeared in the 1974 film “Thunderbolt and Lightfoot.” But Lennear left the music business in the early 1980s to become an educator.

“I had just kind of dropped off the face of the earth, but this movie has allowed many of us to resurface,” Lennear said.

“What’s really curious about it is that all of us went through the same sort of things, we all shared so many experiences that we didn’t know we were sharing at the time. But now we’re finding out, ‘Wow, that happened to me, too.’ I have learned a lot from the movie.”

Hill, youngest of the film’s subjects and a one-time backup singer with Michael Jackson, is trying to step into a solo career. Learning the way her story echoes the stories of those who went before her has been encouraging.

“It just shows me that it’s okay to make mistakes, it’s okay to fail. You can get back up again and you’re stronger,” Hill said. “The power of the women in the film and how they’ve overcome hardship is inspiring. Realizing in my life, even when things don’t turn out the way you want, you’re on your path.”

The excitement surrounding “20 Feet From Stardom” has been tempered by Friesen’s death in December from leukemia. He had seen the finished film and knew that it was premiering at Sundance, but his absence made the experience bittersweet.

“As great as this whole thing has been, I still can’t believe that he’s not here,” Neville said. “It’s cool, but it would have been so much better if he was here.”

20 Feet From Stardom

PG-13. At area theaters. Contains some obscenity and sexual material. 90 minutes.