How does copyright law treat adaptations of books, music, and films?

Under intellectual-property law, copyright owners hold the exclusive right to prepare derivative works, which includes making adaptations of books, music, and films. Because this is a protected right, creating an adaptation generally requires authorization from the copyright holder.1

However, the treatment of adaptations depends on the status of the original work:

• Protected Works: If a work is under copyright, unauthorized adaptation is generally considered an infringement of the owner's exclusive rights. While the doctrine of fair use may provide a legal defense in specific circumstances—such as for parody, criticism, or scholarship—this is not absolute and is subject to judicial interpretation based on factors like the purpose of the use and its impact on the original work's market.12
• Public Domain Works: Works that have entered the public domain are free for anyone to adapt, reproduce, or distribute. Furthermore, while the original material remains free to use, a new, sufficiently original adaptation—such as a translation or a new arrangement—can qualify for its own separate copyright protection.3