THEY have been ‘Lost in Music’ since the 1970s and their global hit, We Are Family, even helped the United States to recover in the aftermath of 9/11.

But – sticking to the messages in their songs about solidarity and family – Sister Sledge have never forgotten their roots.

They have travelled the world and were one of the shining lights of the disco scene yet some of the sisters’ fondest memories are with their grandmother Viola Williams. She taught the young siblings to sing and got them into music venues that they had previously been turned away from.

Kim Sledge said: “She was hilarious. She was one of those dry humoured people and always had a joke up her sleeve.

“But she was opera singer so she got in a lot of places we couldn’t get in to perform.

“She had such courage. She would just walk up and say: ‘I’m the children’s grandmother’ and they would open the door for us. That happened quite a bit.

“We did all kinds of stuff. One day we might have a show in a funfair in Oakland, California, and the next day we might be playing somewhere palatial in France. That’s how varied things were. She was very proud and whenever we came home we would go back to grandma’s church and sing.”

Kim also remembers her grandma’s advice.

The 59-year-old added: “Always be prepared to perform if everything else fails. You can’t rely on music, you can’t rely on microphones – just be able to take to the stage and just go for it if everything goes out.

“That literally happened to us. We had 80,000 people in one stadium when everything went out. All we had was one light powered by a generator so we started clapping and singing – and it worked.”

Some of Sister Sledge’s audiences in the early days started feeling like family too.

Kim said: “There was this couple who used to come to every club we were at. They would drive to all the clubs in New York and Washington and they were an elderly couple.

“They would walk in and she would come out of the bathroom and look like a teenager. They completely changed their outfits to be dancefloor ready.

“We came to love these people and they were having a blast. They fit right in. Just seeing that and how much they enjoyed being on that dancefloor was a highlight for me.”

The sisters did enjoy some of the showbiz perks though, most notably being teamed up with Nile Rodgers and Bernard Edwards, who produced their breakthrough and now iconic 1979 album, We Are Family.

Kim added: “It was exciting because they were new and the record company was looking for an act to team them up with.

“We had been performing for a while professionally and it was interesting working with them because they had a whole different concept. They were very spontaneous so we changed from the school of thought of walking into the studio and being prepared to spend lots of money and time to getting it all down straight away.

“It was like ‘hit it, quit it, get out’. They wanted completely raw spontaneity. They were looking for magic and it worked. It became like a party.”

Over the years Sister Sledge have performed for President Clinton and more recently the Pope at the World Festival of Families in Philadelphia.

But Kim said the person she enjoyed meeting the most was the late blues icon B.B. King.

She said: “He had a mastery of gift and he was so humble.

“He was just a nice person who was always willing to share and he would come and give us advice on things. His words were always encouraging and comforting and simple. You didn’t need to sit there and look at him like he was an oracle. He felt more like an uncle.”

n Sister Sledge headline Rewind North 80s music festival at Capesthorne Hall on August 5. For tickets visit rewindfestival.com/north