Once a copyright runs out on a book or a piece of music, it can legally be placed on the internet for anyone to download.
In 1988 the U.S. Congress extended the copyright protection to 95 years after the year of original publication for corporations. But copyrights holds for 50 years in Australia and 70 years in the European Union.
Discuss how you as the book or music publisher (you hold the copyright) would price your book Gone With the Wind (published 1939) and music Elvis Presley's 1954 hit "That's All Right" in the three different markets.