NEW YORK • The song has rung out at marches and vigils throughout the country over the past week: We Shall Overcome.

With its message of solidarity and hope and its legacy as a civil rights anthem, it has become a symbol of peaceful protest. Along with Woody Guthrie's This Land Is Your Land, it is so deeply woven into the country's fabric that it is considered an American treasure.

Both songs are considered private property, however, since each of them enjoys copyright protection. But that status could soon change, through a pair of lawsuits that seek to have the songs added to the public domain.

They would then join Happy Birthday To You, a formerly copyrighted classic recently ruled to be among the creative works available for any and all to use as they choose.

While money is at the heart of almost every copyright case, the lawsuits over the two songs also have a decidedly political tinge - they seek to decide who gets to co-opt the message of songs that were written in service of a particular point of view.

According to Ms Nora Guthrie, Woody Guthrie's daughter, having the copyright for This Land has let her prevent the song from being exploited in ways that her father - well known for his communist sympathies - would never have approved of, including what she said were attempted uses by former United States president Ronald Reagan, the National Rifle Association and the Ku Klux Klan.

"Our control of this song has nothing to do with financial gain," Ms Guthrie, the long-time keeper of her father's cultural legacy, said in an interview.

"It has to do with protecting it from Donald Trump, protecting it from the Ku Klux Klan, protecting it from all the evil forces out there."

Others see the fact these songs are copyrighted at all as anathema to the spirit in which they were created. Adding these songs to the public domain, where they could be freely adapted and built upon by new generations - and where they would generate no royalty payments - is "just part of the folk tradition", said Mr Mark C. Rifkin, a lawyer whose firm has represented the plaintiffs in all three suits.

"And I don't think Woody would be bothered by it at all."

Legal experts say that such cases show the difficulties in determining the proper limits of copyright, which is meant to encourage creators by giving them limited monopolies over their works. Yet the terms have gradually increased with the lobbying of corporate owners.

Mr Rifkin portrayed his firm's music copyright cases as each pitting a struggling artist against a "greedy corporation" that is misusing copyright.

"You've got David and Goliath," Mr Rifkin said. "We usually represent David, not Goliath."

That power dynamic is less clear with We Shall Overcome and This Land. Both are controlled by the Richmond Organization, a mid- sized publisher whose catalogue includes works by Woody Guthrie and Pete Seeger.

Ms Guthrie said she and the publisher refuse most commercial requests for This Land, whose copyright was registered in 1956.

Despite its fame, she said, the song earns less than some tracks on Mermaid Avenue, the 1998 album in which Billy Bragg and Wilco set Woody Guthrie lyrics to new music.

"The joke is that they can never make money off of Woody," she said of the Richmond Organization. "All the requests we get for This Land, whether to show it in a popcorn commercial, a diaper commercial, to really exploit it if we want to - we always say no."

NEW YORK TIMES