What is "public domain?"
Works that fall into public domain can be used without obtaining permission because they are no longer protected by intellectual property laws (copyright, trademark, or patent laws).
January 1, 2021 is Public Domain Day in the US. Works from 1925 have now entered the public domain.
For more information about new releases into public domain, information about future public domain days, and the "Sonny Bono extension," see:
Music in the Public Domain: A List of Musical Titles with Expired Copyrights [...] by