Produced by Nile Rodgers, the 1979 hit "We Are Family" and its album of the same title introduced the sisters of Sister Sledge — Debbie, Joni, Kathy and Kim — to the world in a big way. On July 31 in an exclusive Variety interview, Kim spoke of the upcoming publication of her memoirs and her efforts to bring the story of the four Philadelphia sisters to the big screen with Life Song, a movie feature in development.

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Sister Joni died of natural causes at the age of 60 in 2017. Carrying on, the musical sisters still perform together and are able to look back from the unique vantage point of their industry success. "Music will be a great part of it, because that's what our lives have been about," Kim said. "During some of the most politically transitional moments in history, we were there."

It's true. At Muhammad Ali's 1974 "Rumble in the Jungle" fight in Zaire, the sisters were there performing with James Brown. While America underwent turmoil and change, their family performed as well with the Jackson 5, Elton John and Stevie Wonder. But it all began in Philly learning to sing and read music from their grandmother, opera singer Viola Hairston Williams. Kim is confident she can capture it all on the big screen — after all, she has her family behind her.

Sister Sledge was nominated for Best R&B Vocal Performance By A Duo, Group Or Chorus for "We Are Family" at the 22nd GRAMMY Awards, performing their hit at that year's telecast. Following the group's previous single "He's The Greatest Dancer" ascending to No. 9 on Billboard's Hot 100 a month earlier, the song reached No. 2 in June 1979, setting the tone for the last summer of the 70s.

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