Material that is in the public domain is not protected by intellectual property laws meaning they are not subject to copyright, trademark or patent regulations. No one owns these works so they are free to use without permission. Public domain applies to any work published in the US before 1923 or works published before 1964 for which the copyright was not renewed (renewal was required for works published before 1978). The US Copyright website, www.copyright.gov, can assist you in determining if a copyright was renewed. This can be a gray area so always check for renewals on materials originating in this time period. Chapter 11 of the copyright law (again see the website above) deals with sound recordings and music videos.
Beginning in 2019, the copyright on works published in 1923 will expire and become part of the public domain, then in 2020 the same is true for works published in 1924 and so forth. Copyright does not protect the titles of books or movies, short phrases like “Beam me up” or commonly understood facts and theories like the earth is round.
For works published after 1977, the copyright is intact until 70 years after the author dies; in cases where there is more than one author, the copyright does not expire until 70 years after the death of the last author.
For songs in the public domain, you only need the master use license from the owner of the specific sound recording you’re using.