On New Year's Day 2014, the works of American composer, pianist and performer Fats Waller entered the public domain. That same day, copyright protections expired on the illustrations of British artist Beatrix Potter, the writings of French philosopher Simone Weil and the research bulletins of American scientist George Washington Carver, so that they too passed into the public domain to find new life.  This means that "Ain't Misbehavin" and a wealth of other cultural and intellectual works are now freely available to perform, copy, translate, adapt or republish.

Most work enters the public domain along this same path - through the expiration of copyright protections. But since copyright law is (at least partly) a national jurisdiction, copyright terms vary from country to country. In Canada, New Zealand and Japan, copyright expiration occurs 50 years after the creator's death. This calculation is known as "life+50." In Australia, most of Europe and many parts of South America, copyright expiration is calculated as "life+70."  And in the US, where Congress passed the Copyright Term Extension Act in 1998, no new work will enter the public domain until 2019. So while playing with "Ain't Misbehavin" is now possible in some countries, in others it may still be, well, misbehavin'.  

The public domain is vital to a society's intellectual and cultural life.  It makes creative works available to artists, scholars, fans, teachers and students without demanding permission or payment. It acknowledges the collaborative nature of creativity by making work freely available to reuse.  And it allows for the collection, preservation and distribution of important cultural resources that speak to diverse histories.

This is why many observers worry that the list of "life+50" countries is getting shorter. While digital technologies make the work of building public collections easier, the number of works entering the public domain through the conventional route of copyright expiration may actually be shrinking, under pressure from multinational agreements like the Trans-Pacific Partnership to extend copyright terms. Still, there is reason to believe that the public domain will continue to flourish through actions like making content available through open access licenses, identifying works whose copyright protections have ended, and advocating for reduced copyright terms, all strategies developed by digital users themselves.