As a producer I know that samples need to be cleared. How are news programs treated for inclusion in musical works. Are some historical works public domain (Kennedy moon mission speech is a good example). What about current news, NPR, etc?
In the US, fair use, the doctrine of copyright law that permits limited use of copyrighted material without needing to obtain permission first, is measured by four criteria. It doesn't matter whether the work you are including or creating is music, text, or a newscast, the same four criteria apply.
- The purpose and character of the work you are including the copyrighted material in. For example, are you using it for educational purposes or are you trying to profit from what you are making?
- The nature of the material you are including.
- The amount of the work you are including, in relative and absolute terms. Are you including 5 seconds of a 1 hour work or all 10 lines of a poem?
- The effect on the market or value of the included work. Are you going to take sales away from the included work?
However, there is no checklist to determine if your use of something falls under fair use. There is no guarantee that if you are, for example, using 30 seconds of a newscast for for educational purposes that will have no impact on the broadcaster's ability to sell commercials that you fall under fair use. Or that you tip the scale at 31 seconds of included material. Or that any commercial purpose of your work isn't fair use. "The only way to get a definitive answer on whether a particular use is a fair use is to have it resolved in federal court."
Historical material is not automatically public domain nor is it automatically available for fair use. Figuring out if a work's copyright is still in force is rather complex. You need to sort through the correct copyright term for the original work and whether any extensions have been applied.
However, any U.S. government work is automatically in the public domain. But there are exceptions to that. You can't just assume that because you found it on a government website that it is a government work. Something, like an NPR broadcast or a medical study, does not automatically become a government work and public domain just because it is partly or fully funded by the federal government.