Joni Sledge, one of four sisters who together sang one of disco's most enduring songs with "We Are Family," has died, a representative said Saturday. She was 60.
The singer died at her home in Arizona on Friday with the cause of death yet to be determined, publicist Biff Warren said.
"We miss her and hurt for her presence, her radiance and the sincerity with which she loved and embraced life," a family statement said.
Daughters of two performers, Joni and her three sisters -- Debbie, Kathy and Kim -- grew up in Philadelphia and enjoyed moderate success touring in the 1970s with R&B songs.
But the sisters found a major hit in 1979 with "We Are Family," which was written by Nile Rodgers and Bernard Edwards, who had emerged as key figures in the disco craze with their band Chic.
Joni Sledge, in an interview last year with The Guardian, said the sisters had become professionally frustrated by the time they made "We Are Family" and had considered other careers, such as studying law.
"Recording the track 'We Are Family' was like a one-take party -- we were just dancing and playing around and hanging out in the studio when we did it," she said.
Rodgers offered condolences on Twitter, saying, "We did something pretty amazing together."
Despite the message of family unity, Kathy Sledge left the group to pursue a solo career and tensions ensued, with Joni and Debbie remaining the core members.
Sister Sledge came together in various forms for performances that included the massive Festival of Families by Pope Francis in Philadelphia in 2015 and last year's presidential campaign of Hillary Clinton.
Joni Sledge, speaking in 2015 to Women's Wear Daily, said that the group's main hit -- with its chorus, "We are family / I got all my sisters with me" -- carried a time-tested message of unity.
"It's just as powerful today. That's one of the good things about it. It teaches respect," she said.