The radio signals were color-blind. Like the Internet, they didn’t break down barriers as much as live in a world separate from them. The birth of the civil rights movement was intimately bound up in the spread of jazz music throughout the United States. It was, for many Americans, the first cultural common ground between black and white America that had been largely created by African-Americans. That in itself was a great blow to segregation. Martin Luther King Jr. made the connection explicit in remarks he delivered at the Berlin Jazz Festival in 1964:

