They stormed the charts in the late 1970s with their hit feel good tune "We are family" - but now they are hoping to instil that value into estates blighted by the gun crime culture.
Sister Sledge: Family values are important
Disco divas Sister Sledge arrived at the House of Commons saying it was their duty as entertainers to speak out against the gun culture which is claiming so many lives.
Joni and Debbie, two sisters from the group, joined So Solid Twin MCs Dwayne and Noel Thomas to give their support to a report by MPs which calls for more police officers to be allowed to carry arms to tackle gun crime.
And the artists' messages were well received with big applause from families of shooting victims and groups trying to combat the scourge of gun crime.
Joni told the gathering that it was time to change the culture behind the violence.
"We feel it is extremely important for entertainers to speak out especially about something as horrific as gun culture," she said.
"In America we have had some horrific events because of the illegal use of guns. We have always admired Britain for not having guns as legal.
"Particularly with the policemen, we think it is wonderful that they have bobby-sticks and not guns."
"There are so many senseless crimes, especially involving youth."
Joni said she and her sister became involved in anti-gun campaigning after seeing a young Japanese
student shot dead on the streets of Los Angeles.
"Statistics don't mean anything when a person gets killed."
She stressed: "We're here as artists saying we have a big mouth out there. We can speak to a lot of people and we feel a big responsibility ...
"We just say there has to be an effort that now includes ... government and police, but also community issues of building self esteem and building relationships and families."
Her sister Debbie added: "It's an issue that we are passionate about, not just as artists, but as parents."
Dwayne Thomas, one of the So Solid Twin MCs from controversial rap collective So Solid Crew, said: "As artists we feel we have to speak out."
He said young people needed more youth groups and other community to keep them out of trouble.
His brother Noel Thomas added: "If people put something into the community
the world can be a better place."
Lucy Cope, whose 22-year-old son Damian died after being shot in the stomach in Holborn, central London last summer, was particularly impressed by the appeals and applauded vigorously.
Mr Cope was shot outside a nightclub
But Mrs Cope, from Peckham, said she was angry that the government had failed to put plans for a five-year minimum sentence for illegal possession and use of a firearm into action.
"The government should hang its head in shame. When is this going to happen? How many more people must die before this is introduced?
"Give out the five year minimum sentence for possession of a firearm. No mitigation,"
Mrs Cope, who founded the Mothers Against Guns group which campaigns for a change in firearms laws, said she will be pressing the issue when she meets Home Secretary David Blunkett later this month.