For nearly two decades, Morgan Neville has defined himself as one of the most prolific documentary producer/directors of American pop culture. Beginning with his 1995 film Shotgun Freeway, which imagined a history of Los Angeles through the eyes of its denizens like James Elroy and Buck Henry, Neville has explored the lives and work of such artists as Muddy Waters, Hank Williams, James Brown, James Taylor, Iggy Pop and a host of others. His latest film,Twenty Feet from Stardom, profiles the unsung songstresses of rock 'n' roll—the backup singers you've heard but not heard of.

"What I realized early on is that telling the unfamiliar story behind the familiar is something that has always been of interest to me," Neville maintains. "Even going back to Shotgun Freeway. It was a way of retelling LA history from a kind of microscopic point of view. Everybody has an idea of Hollywood or LA history, but let's find out what the invisible history is about it, so when you think about LA, you will think about it differently.

"That's certainly been happening with Twenty Feet from Stardom," Neville continues. "It changed how I hear music and hopefully it changes the way others will. I spent a couple of years while working on this with the radio on, suddenly hearing vocals in songs I've heard a thousand times and realizing just how they were constructed and how important those background vocals were. Being able to take a song and share it anew—I love that. It just adds so much more depth to things we take for granted."

In the film, Neville focuses on a group of African-American backup singers, spanning several generations. The story begins with Darlene Love, who, with her trio the Blossoms, helped break the color barrier for black backup singers in the early '60s. While Love has sung on recordings by everyone from Elvis Presley to the Beach Boys, it was her decades-long tumultuous work relationship with record producer Phil Spector for which she is best known. Her tale is certainly the most tragic and triumphant, and becomes the thread of the film.

The other singers we meet all credit Love as a major inspiration, including Merry Clayton, who most famously sang backup on the Rolling Stones' classic "Gimme Shelter"—while in curlers and silk pajamas, and pregnant. Clayton was also one of Ray Charles' backup singers, and sang on hits like "Sweet Home Alabama." There's Claudia Lennear, who started out with the Ike & Tina Turner Revue, then worked with the Rolling Stones, Joe Cocker and George Harrison. Both Clayton and Lennear tried to walk those "twenty feet to stardom," but never really succeeded. On the other hand, there's Lisa Fischer, who, despite winning a Grammy for her solo album in 1991, returned to being a backup singer and has been touring with the Stones, among others, since 1995. The youngest of the bunch is Judith Hill, who was thrust into the limelight after singing at Michael Jackson's memorial in 2009, and is currently trying to straddle her blossoming stardom while continuing to pay bills as a backup singer.

But the genesis of Twenty Feet from Stardom, and Neville's participation in it, is a story unto itself. The reason this film even exists, Neville acknowledges, is due to the film's producer, Gil Friesen, former president of A&M Records from 1977 to 1990. "Gil told me when we first met what his inspiration was for the film," Neville recalls. "He had gone to a Leonard Cohen concert with his wife, and beforehand had smoked a good joint and spent the whole concert fixated on the three backup singers at the front of the stage, wondering, 'What's their story?' He woke up the next day and the thought was still in his head. He started talking to people about it and realized that nobody had ever told their story. A lot of Gil's friends told me later that Gil came to them and said, 'I'm thinking about maybe doing a documentary about backup singing,' and there was a lot of skepticism from them. So it took a year for him to actually say, 'I'm going to get this to happen.'"

Friesen, in fact, put up the bulk of the money for the production. "We got a few other investors, though, but I've never done a documentary like this," Neville admits. "I've never had anyone say, 'I'll get the money, don't worry about it.' Now, this wasn't a cheap documentary. It's one thing to get a big budget to make a documentary about, say, the Eagles. It's another thing to get a budget to make a film about backup singers as there was no guarantee that anybody's ever going to want to see it. So it's the kind of film that would never have been made if not for Gil's passion for it.

"Now being a music geek, when I first heard the idea of backup singers, I knew it would be interesting to me, but I had no idea what it was going to be," Neville continues. "And I thought I had a gaping hole in my musical knowledge. But in talking to my music geek brethren, I realized nobody knew much about backup singers. Nobody had written a book about them. There are no articles about them. No websites. It was really difficult to get any information about how that world works, other than talking to actual backup singers."

Initially, Neville and his collaborators weren't even sure they were going to make the film until they sat down and started interviewing singers. "We did 50 oral histories with backup singers," he explains. "And out of that, that whole world instantly became dimensional to me and I got the ideas and themes and the characters. From that, I wrote a treatment and then we went ahead and made the film."

But how did he decide which characters to follow after all those interviews? Neville says it wasn't easy. However, Love instantly stood out and he knew she would be a big part of the movie—but not that she'd be the thread.

 "I tried to get a number of singers whose lives kind of dovetailed with each other," Neville says. "They came from a similar enough experience, that even though we have a number of different main characters, they weave together into kind of a meta-character that we understand, that they're all going through the same thing. But each of these characters also comes from subsequent generations of backup singers. So through them we also get a sense of the sweep of pop music history through those times. And these singers have incredible voices, are incredible characters, and ideally sang on some big hit songs."

 There are many types of experiences in the world of backup singers, but Neville chose the core experience. "I wanted people who, for the most part, were real voices for hire—who would go into all kinds of sessions, never knowing what they had to do, and have to nail it; the real kind of session people," he explains.

"Gil told me he wanted to make a movie about background singers," recalls Fischer, who has sung behind artists including Luther Vandross and Sting. "He told me the story about how he went to see a concert and was really drawn into the background singers and was curious as to what their lives were like. And I thought, 'Oh, okay.' I know what my days and nights are like, but you never think that your days or nights are going to be interesting to anybody else, except maybe other people who do what you do."

She adds that perhaps the greatest thing for her about doing the film was the chance to meet the other singers whom she had loved for so long but, like most people, hadn't really known their stories. "Because of Merry, because of Darlene, because of Claudia, all the people who were doing this before I started even thinking about doing it, they inspired me and I had no idea who they were," Fischer says. "But to actually meet them and hear their stories, and watch everyone's purpose unfolding and continuing to do so—I feel really thankful for what they went through."

 "I initially had problems with the title of the film," Neville admits, "which Gil had in his head from the beginning, but I felt like people would think, 'Oh, isn't it sad they're not famous.' And there are times you should think that, but there are also times when it's great not to be famous. In America, we love to build up stars. And that's something everybody's supposed to want. But I love the idea of celebrating people who are selfless, because we don't do a lot of that, even though it's getting harder and harder to eke out a living in the creative field.

"The film is ultimately about how very few people accomplish every dream they have, and that the real measure of a person is how you come to terms with the life that you have, not the life you dreamed of having," he adds. "Some people do it with grace, and some people do it horribly."

Having Friesen on the project made the documentary easier to create, according to Neville. "You can't just pick up a camcorder, edit it on your laptop and put it out," he says. "Having someone like Gil made it possible to get some of the songs, and the people who did interviews for the film. But what was amazingly rewarding was not only did he reconnect with people from his past, but he was giving a lot of these people a platform for sharing their stories. And then the most amazing miracle of the whole thing is that it's actually changing people's lives, and that's something Gil didn't live to see."

After a year and a half in production of the film, Friesen's physical health began to fail due to complications from leukemia. But, Neville says, Friesen refused to let his health issues stop him from continuing his involvement in the film. "We had business meetings in his hospital room," he recalls. "He was working full-on almost to the end and I think he loved it. All of Gil's friends and family have been amazing in terms of stepping in and helping, and they're still doing all kinds of things for us."

Friesen passed away in December 2012. Neville says he was very grateful the producer was able to view the finished film and also learn of it being accepted into the Sundance Film Festival. When the film premiered there in January, it was the first film at the 2013 festival to sign a distribution deal, with The Weinstein Company.

Neville recalls that during their first meeting, Friesen told him he only had three goals for this film: "'One, I want to make the best film we could possibly make to celebrate backup singers. Two, I don't want to lose money. And three, I want us to have fun.' I think all those things are going to come true."

 According to Neville, all kinds of new things have happened to the women in the film before it even came out, just due to the film. "There's been a lot of talk about putting together a tour if the film does well," he reveals. "It seems like a fantasy to me, but you start to think about Buena Vista Social Club, Searching for Sugarman or Standing in the Shadows of Motown—and those all led to tours, so why not?"

Neville is currently working on a documentary about cellist Yo Yo Ma and his Silk Road Project, and producing a documentary about the Kenyan music/film collective Just a Band.

Twenty Feet from Stardom begins a limited theatrical release June 14 through RADiUS-TWC.

Ron Deutsch is a contributing editor to Documentary Magazine. He has written for many publications including National Geographic, Wired, the San Francisco Weekly, and the Austin American-Statesman. He is currently associate-producing the documentary Record Man, about the post-war music industry, and lives in Austin, Texas, with his trusty cat, Miles.