"Copyright is a form of protection provided by the laws of the United States (title 17, U.S.Code) to the authors of “original works of authorship,” including literary, dramatic, musical, artistic, and certain other intellectual works. This protection is available to both published and unpublished works."
"Copyrightable works include the following catagories: 1. Literary Works ; 2. Musical works, including accompanying words ; 3. Dramatic works, including any accompanying music ; 4. Pantomimes & choreographic works ; 5. Pictorial, graphic and sculptural works ; 6. Motion pictures and other audiovisual works ; 7. Sound recordings ; 8. Architectural works."
The information above comes from Copyright Basics
The basic term for copyright protection for works today is the author's life plus 70 years. For works made for hire the copyright lasts for 95 years from publication or 120 years from creation, whichever is the shorter. Copyright for works created before 1978 have different rules and copyright for foreign works are unique, longer and terribly complicated!
Works are protected automatically. "Once you create an original work, and fix it on paper, in clay, or on the drive of your computer, the work receives instant and automatic copyright protection." Columbia Copyright Advisory Office.