Under certain circumstances, works that would normally be copyrighted are not protected by copyright law. When a work that would normally be protected is not protected by copyright law, that work is said to be in the Public Domain. When a work is in the public domain, anyone is free to exercise any of the rights that a copyright holder would normally have. For example, if a work is in the public domain anyone can copy, sell, or perform the work since no one owns the rights to it.
The main reasons a work can be in the public domain are as follows:
- It was published before 1923
- It was published between 1923 and 1963 without a copyright notice
- It was published between 1923 and 1963 with a copyright notice, but the copyright was not renewed
- The author placed it in the public domain
- Copyright has expired on that particular work
- It was created by the U.S. government (including speeches by government officials in the line of their duties, official government web pages, and acts of Congress)
As with all questions of copyright, be sure to do your research into the work you want to use to be sure of its copyright status. These are general guidelines and each work is a unique case as to whether it is in the public domain or not.
Copyright Term and the Public Domain in the United States: Details on how long copyright protection lasts on different types of works.