Joni Sledge, who has died aged 60 of unknown causes, was one of four siblings who banded together to create the music group Sister Sledge. Formed in Philadelphia in 1971, their career really lifted off after they were put together with the writer-producers Nile Rodgers and Bernard Edwards (the masterminds of Chic). With the sisters, the prolific pair set about creating We Are Family (1979): it became one of their most memorable achievements, and the group’s definitive album.

The women had been touring regularly on the US east coast in the early 1970s and, after releasing their first album, Circle of Love, in 1975, had begun to build a following in Europe too. Yet they had no idea what Rodgers and Edwards had in mind until they arrived at the recording studio that day.

Sister Sledge: We Are Family

As Rodgers recalled in his book Le Freak: “The first time we met Sister Sledge was also the first time they heard the song We Are Family. When they walked into the studio, we were still writing the song as it was blasting over the loudspeakers … Once we had finished, we gave it to them and basically said: ‘Here it is and here’s how it goes!’”

Though Joni commented in the Guardian last year that “recording We Are Family was like a one-take party”, Rodgers and Edwards had a specific way of working that did not leave much space for different ideas from the artists. However nobody could argue with the results. The first single, He’s The Greatest Dancer, was a No 9 pop hit in the US and No 1 on the R&B chart. We Are Family went to No 2 on the pop chart and again topped the R&B listing, with both tracks entering the British Top 10.

A third single, Lost in Music, fared poorly on the US charts (though it made the UK Top 20), despite being a haunting, trance-like piece of work. Joni sang the lead vocal on it and, as her sister Debbie commented, “the words are about determination, not giving up, so they kind of fitted where we were at the time”. The We Are Family album went to No 3 on the Billboard Hot 100 and topped the US soul albums chart. Rodgers remarked: “Pound for pound, I think We Are Family is our best album hands down.”

Born in Philadelphia, Joni was the second of four daughters of Edwin, a tap dancer on Broadway, and his wife, Florez (nee Williams), an actor. Joni and her sisters, Debbie, Kim and Kathy, received voice training from their grandmother Viola Williams, a former operatic soprano, and gained early experience singing at the family church, Williams Temple Christian Methodist Episcopal.

Joni Sledge, right, performing with her sisters in their disco heyday. Photograph: Echoes/Redferns

After forming Sister Sledge, they recorded their first single, Time Will Tell (1971), for the Money Back label and had their first UK Top 20 hit in 1975 with Mama Never Told Me. Also that year, they made Circle of Love, from which the single Love Don’t You Go Through No Changes on Me was a breakthrough hit in Japan, then recorded a second long-player, Together (1977), in Germany.

We Are Family elevated their career to a new plane, but they could not sustain its enormous success. The follow-up album, Love Somebody Today (1980), fell far short of its predecessor, though it delivered modest hits with Got to Love Somebody and Reach Your Peak, and helped to sustain the sisters on a three-year campaign of international touring. They switched to producer Narada Michael Walden for All American Girls (1981), and the following year self-produced The Sisters, which brought them a Top 30 pop hit with a version of the old Mary Wells track My Guy.

In 1984, they enjoyed a fresh spurt of chart activity with a re-release of Lost in Music, which had been remixed by Rodgers and reached No 4 in the UK, and also had a UK No 11 hit with Thinking of You, belatedly extracted from the We Are Family album. In 1985 they topped the British chart with Frankie, from their album When the Boys Meet the Girls.

Sister Sledge perform Lost in Music, with Joni as the lead singer

In 1996, Joni wrote the song Brother, Brother Stop after witnessing a shooting incident in Los Angeles, and it was recorded for a Sister Sledge greatest hits collection. She also wrote several of the songs on, and produced, their album African Eyes (1997), which was nominated for a best-production Grammy.

In 2001, Sister Sledge (including Kathy, who had left to pursue a solo career in 1989) recorded an all-star version of We Are Family as a post-9/11 benefit disc. Joni and Debbie performed on the Pyramid stage at Glastonbury festival in 2005, with Kim, now an ordained minister, rejoining them to perform for Pope Francis at the World Meeting of Families festival in Philadelphia in 2015, alongside Andrea Bocelli and Aretha Franklin.

Kim said of Joni: “She’s always been able to hear and see more and also know what’s coming, and I think it’s because she’s got that pulse within.”

Joni is survived by her son, her sisters, Debbie, Kathy and Kim, and their half-sister, Norma Carol.

• Joni Sledge, singer and songwriter, born 13 September 1956; found dead 10 March 2017