How does one discover if either books or music are out of copyright?

The only possible way to know starts with when the book or music was first published and where and by whom. As a general rule, music in the USA is copyrighted "forever" (i.e., 95 years or more), but foreign works may expire 50 to 100 years after the original composer dies. Music recordings published in the USA prior to 1972 are copyrighted under state laws which are only preempted by federal law in 2067, and state law copyright never expires.

Once you know the date and location of the publication of a composition or a book, you can look in the attached chart to determine what requirements there were, if any, and look in the US Copyright Office records to see if those requirements (if any) have been met.

Anything created in the USA in the last 120 years and NOT published may be still copyrighted, and anything created since 1989 IS copyrighted and anything PUBLISHED prior to 1923 is public domain (no copyright) and anything else would depend upon when and how it was published. For instance, if published prior to 1989 without copyright notice, it lost any ability to be copyrighted in the USA, unless it was first published in a foreign country and had not expired before 1996 (under 17 USC § 104A)...

I wrote this in April of 2011, presently after the shooting of Trayvon Martin-- no longer the shortest call, yet a contender for the shortest poem, and actual the shortest non-ironic poem on a updated difficulty: call: "For Trayvon Martin" text fabric: 'Emmett till at last... ...nonetheless.' To be study with an emphasis on the pause.

the quick way is to see if a book is in gutenberg.org

maybe this ehow article will be more useful to you http://www.ehow.com/how_7554868_public-domain-work...