Figuring out what is protected by copyright can often be better answered by understanding what is not protected.
Copyright protection is only for those elements of any work by an author that are original and fixed in some tangible means. (See What is copyright).
U.S. copyright law excludes a number of different things that are found in many, if not most, works.
Copyright protection for a work does not extend to pre-existing material. It is only provided for those portions of a work that result from original authorship.
A composer is researching a music copyright to determine if it has expired for a piece that has a segment he wants to use in his composition. He determines that it has not. Desiring to use it anyway, he contacts the heirs of the piece’s “author” in the hopes of getting permission to use the segment.
(continued at Copy Right, Copy Sense)
Post from one of my abandoned blogs – North Farnham Freeholder – recovered from Internet Archive WayBackMachine 3/1/2011