WASHINGTON (AP) — The Supreme Court has heard arguments over a law that extended copyright protection to millions of works by foreign artists and authors that had been in the public domain - meaning they could be performed and used in other ways without paying royalties.

Community orchestras, academics and others who rely on uncopyrighted works are challenging a 1994 law that made copyrights available to the foreign works. Google, with its YouTube and digital art and library projects that depend on works in the public domain, is backing the challenge. Composers, authors, songwriters, photographers and others who depend on copyright protection are urging the court to uphold the law.

The court has never said whether published works lacking a copyright could later be protected.