Determining whether or not a work is in the public domain by using copyright term duration (by date) can be complicated.  Please also see the "Definitions" tab for other kinds of works that do not qualify for copyright protection.  The charts you see to the right provide basic information on the length of copyright term for different kinds of works. 

• Literary, musical, dramatic, audiovisual, motion pictures, and visual art is all included in the first chart.
   
• The second chart focuses on sound recordings since the copyright durations are treated much differently than the others; here is a link to more information that explains why there is a difference.  Recent legislation has changed some of these durations; please consult this duration chart from Cornell University Libraries for more information.   
   
• Next, each category is divided into whether or not the work is published. 
   
• Look at the "Qualifications" column to check for other important aspects of the work you would like to use.  For instance, see whether or not a notice was placed on the work (look for "c" in a circle then the copyright holder's name with a date; or check out Circular 22 from the U.S. Copyright Office and refer to page 5), or if the item was written anonymously.
   
• Look to the last two columns to see what the duration of the copyright term would be for that work. 
   
• If you cannot make a determination whether or not a work is in the public domain, then it is likely that it's still covered by copyright.  Consult with an attorney who specializes in intellectual property law for further assistance.  

Please keep in mind that this chart only deals with works published or created in the United States.  This chart covers the basic areas of determining how long a work is covered by copyright.  For more detailed information, as well as copyright durations of foreign works, please consult Peter Hirtle's chart, "Copyright Term and the Public Domain in the United States", or Michael Brewer's interactive web tool: Digital Copryight Slider.  You can also check the U.S. Copyright Office's Catalog of Copyright Entries to see when a work may have been registered (Digitized through University of Pennsylvania); however, this kind of searching can also become complex.  

Copyright durations for sound recordings (All information in this chart is paraphrased from Cornell University Library's "Copyright Term and the Public Domain in the United States" guide).

Besek, J. (2005).  Copyright Issues Relevant to Digital Preservation and Dissemination of Pre-1972 Commercial Sound Recordings. (CLIR Publication no. 135). 

Besek, J. (2009). Copyright and Related Issues Relevant to Digital Preservation and Dissemination of Unpublished Pre-1972 Sound Recordings by Libraries and Archives. (CLIR Publication no. 144). 

17 U.S.C. § 301-305 

Cornell University Libraries. (2022). Copyright Term and the Public Domain in the United States.

Fishman, Stephen. (2010). The Public Domain: How to Find and Use Copyright-Free Writings, Music, Art and More. Berkeley, CA: Nolo.

U.S. Copyright Office. (2003). Duration of Copyright: Provisions of the Law Dealing with the Length of Copyright Protection. (United States Copyright Office Circular no. 15a).

U.S. Copyright Office. (2010). How to Investigate the Copyright Status of a Work. (United States Copyright Office Circular no. 22).

Disclaimer: This tutorial on using public domain materials, Creative Commons licensed materials, and copyright law is provided for informational purposes only!  I am not a lawyer and cannot provide legal advice.  None of what you read in this tutorial should be construed as legal advice.  Should you require legal advice, please contact an attorney.