20 Feet From Stardom, from music documentary veteran Morgan Neville, is a film entirely devoted to the overlooked lives and jobs of back-up singers. Everything from the sound and vision to the impeccably selected archive footage to the beautifully shot recording sessions is wonderful. Neville isolates the tracks on well-worn records, forcing us to examine them again. Not that anyone needs to write any more praise of "Gimme Shelter," but isolating Merry Clayton’s vocals is spine-shivering.

While the documentary focuses on individual careers, like Clayton's, it evolves into a larger piece of criticism about the music industry, our fame-centric definitions of success, and a star-focused arts culture. Though Neville has interviewed some of the most notable singers in the spotlight today—Bruce Spingsteen, Sting, Mick Jagger, Sheryl Crowe, and Stevie Wonder—he expertly navigates our attention away from these stars to focus on the people that are behind them: the backup singers.

Darlene Love, Lisa Fisher, Merry Clayton—these aren't names or faces you necessarily know, but as Springsteen puts it, we have an “allegiance to their voices.” They're Grammy winners and Top 40s toppers, and their stories run the gamut of familiar music industry pitfalls—the bad management, overwhelming pressure, mismatched producers, and mismanaged money. Still, the way Neville demonstrates their talent and dedication to music, it's increasingly perplexing why the world let these voices get away.

Though it's about pop music, 20 Feet From Stardom is a feminism verging on activism documentary. It's about a group of people who were often unfairly overlooked, whose talents were too frequently used and discarded without due credit. By focusing on the background, it changes the way you look and listen.

Dr. Mable John, a blues vocalist and one of Ray Charles's Raelettes, puts the individual stories in a larger context:

“We in the music industry especially African American people, we need to know our worth; we need to know, as women, we're important. I think the breakdown is, when a woman doesn't know what she is and she settle for less. Check out your worth because you're worth more than that.”

The story of Merry Clayton is one of the most powerful in the film. She joins the Rolling Stones in the middle of the night, curlers in her hair and turns her initial shock at singing “rape, murder” into a screaming, powerhouse delivery. She says she suffered a miscarriage on the way home due to the emotional and physical strain of singing. Then her name was incorrectly written as "Mary" in the original record release. Everybody asked why she wasn’t a star. She doesn’t know.

Darlene Love’s vocals were also miscredited, but in an outrageously purposeful scheme by Phil Spector, rather than a likely careless mistake. Singled out by Spector for his Wall of Sound, she ghosted for the Crystals, singing "He's a Rebel" and sending the song to the top of the charts while the touring band never even heard it before it aired. Her voice was on dozens of Top 40 tracks, ghosting and backing Sam Cooke, Dionne Warwick, Frank Sinatra. When she tried to record under her own name and take credit that was hers, Spector continued to box her in—and Love eventually fell so down on her luck she started cleaning houses. It wasn’t until she heard herself singing “Christmas (Baby Please Come Home)” while cleaning a bathroom, that she decided to try to take back her talents. She was inducted into the Rock and Roll Hall of Fame in 2011 after years of obscurity.

Sting, a man with boundless success, speaks beautifully and sadly on slights likes these:

“It's not about fairness, it's not really about talent, it's circumstance, it's luck, it's destiny, I don't know what it is, but the best people… deal with it.”

You want him to say that the best people will succeed. But he knows better than that. Levels of success vary throughout the film. Some singers seem to have been partially destroyed by this world, others adopt a take it or leave it attitude—continuing to devote themselves to music but avoiding the play for fame.

Apart from one misguided sequence (several of these singers come together to record the stupidly saccharine “Lean on Me”), the emotions and bittersweet or triumphant moments of 20 Feet From Stardom are not sappy or grabby or forcing you what to feel. It doesn't come to a neat conclusion, but leaves the stories in ambiguity—as you sense that the singers also look upon their careers with ambivalence.

20 Feet From Stardom is a model documentary. It gives thorough, dedicated attention to something that could have otherwise gone overlooked and it changes the way you think and listen. And of course, it sounds fantastic. In the lovely words of Jo Lawry, a singer with Sting, the joy of singing "back-up" is that "something that happens when you lock in with somebody and all the harmonics ping. And if you don't like that, what do you like?"

20 Feet From Stardom premieres June 14, 2013 in limited release. To contact the author of this article, email maggie@gawker.com.