06/17/2013 11:34 am ET Updated Aug 17, 2013

Walking the Walk: Twenty Feet from Stardom

She may not be as famous as her sister in soul, Aretha Franklin, but that does not make Merry Clayton any less of a diva. Her story may be famous in music history: as told in the documentary Twenty Feet from Stardom, pregnant and in curlers, she got a call in the middle of the night to sing with The Rolling Stones. That haunting riff at center in Gimme Shelter, the one you think of, almost a howl, "rape, murder, just a shot away," that's Clayton. Even Mick Jagger seems amazed at how the sound was made. Filmmaker Morgan Neville had to admit, after making this documentary about backup singers, he can never listen to music the same way again. Audiences are likely to feel the same.

And it's not just the music. The world of backup singers resonates with themes of racism, sexism, and greed. Bruce Springsteen explains the relationship to gospel, to church practice of call and response. In the case of Darlene Love, for example, Phil Specter had her under contract with The Blossoms; to her surprise, she created a hit sound broadcast everywhere. She was not credited for vocals on a holiday album. She quit music for years, and cleaned houses for a living. Ike Turner imagined himself a pimp, with his singers, including wife Tina, his "ho's." By contrast with the backup sounds that preceded the glory days of rock, say, Perry Como and his bland shirt-waisted, coiffed white vocalists, the incredible innovation was to shine a spotlight on the "colored girls" as in Lou Reed's song. As Sting explains, extolling the chops of Lisa Fischer, she's a star. Set her free.

This weekend, Fischer was on hand for the Summerdocs screening of the film at Guild Hall, a collaboration between the Hamptons International Film Festival and The Wall Street Journal. Fischer is perhaps the un-diva. After a Q&A with Dick Cavett, she engaged the audience, coming off stage and asking for volunteers to sing with her. She then put their heads against hers and they hummed an intense vibration, proving that we all have this powerful instrument, the voice. Following that, she sang. The film will open the Nantucket Film Festival, but by then, she will fly to London to tour with the Stones.

Interviewed last week at the Royalton Hotel, Merry Clayton recalled becoming a Raelette in the '60's, as Ray Charles' singers were known. Having worked behind just about everyone, she said she has yet to perform with Bono. Bono, are you listening?

A version of this post also appears on Gossip Central.