Mary Wilson has urged Illinois lawmakers to make it illegal for impostors to perform as original artists.
Wilson's visit was part of a national campaign to get bills passed in several states that would ban knockoff groups. The goal is to eventually make it a federal law, she said.
"They've crossed the line between imitation and flattery to becoming almost like identity theft," Wilson told a House committee Tuesday. The committee later unanimously endorsed a bill that will be sent to the House for a full vote.
South Carolina and North Dakota have passed similar laws.
Wilson, who sang with Diana Ross in the 1960s trio, said she has filed several civil lawsuits against groups claiming to be The Supremes. But she lost all the cases, she said, "because there were no laws to protect me."
Many early performers no longer have rights to their work or famous names because of the language in contracts they signed, said Bob Crosby, president of the Vocal Group Hall of Fame, one of the groups behind the campaign.