At midnight on New Year's Day, an array of songs, films and books from 1923 entered the public domain. That means no more copyright penalties or fees for anyone who wants to use them.What's in this treasure trove? What can we do with it? And how do our copyright laws protect — or limit — creators?Want to support 1A? Give to your local public radio station and subscribe to our podcast. Have questions? Find us on Twitter @1a.