This explains the US landscape. https://guides.library.cornell.edu/copyright/publicdomain https://guides.library.cornell.edu/copyright/publicdomain Belgians w

This explains the US landscape. https://guides.library.cornell.edu/copyright/publicdomain https://guides.library.cornell.edu/copyright/publicdomain Belgians would have to look up their local version of that. But to answer your question is it depends on the country. Les say one country has 100 years. Another has 50. It is now year 75. In the 50 year country and you make a derivative you are fine. But take that same thing to the 100 year country then you might be in trouble. But only if you bring the stuff into that country. Now others may import it but that is on them not you. But you might have to prove that out in court. Also in the US sound recordings can bet more tricky as there are also state laws that come into play.