Copyright protects “original works of authorship” that are fixed in a tangible form of expression. Copyrightable works include the following categories:

• Literary works
• Musical works, including any accompanying words
• Dramatic works, including any accompanying music
• Pantomimes and choreographic works
• Pictorial, graphic, and sculptural works
• Motion pictures and other audiovisual works
• Sound recordings
• Architectural works
• Computer programs

It is best to assume that anything published after 1920 is protected by copyright, even if it does not contain a copyright notice. The Library of Congress Copyright Office Circular 22 explains how to determine the copyright status of a work, when you are in doubt. Helpful summaries of this publication can be found at the website of the Copyright Information Center of the Cornell University Library and the website of the University of North Carolina.