Mark your calendar: January 1, 2003. On that fateful day, untold billions of works now subject to copyright protection will go into the public domain simultaneously, and unless you act now, some of your clients' works may inadvertently be among them. Under § 303 of the 1976 Copyright Act, works created before 1978 but not previously published or registered lost their perpetual common-law copyright protection and became subject to a finite statutory term. Thus Congress ensured that every letter Jack Kerouac ever wrote to his mother, every notebook sketch by Matisse, every Mozart counterpoint exercise, would eventually, someday, lose its copyright protection.
For works created by authors who died in 1932 or earlier, that day is January 1, 2003. If the author died in 1933 or later, or is still living, the term of copyright in an unpublished work will subsist through the last day of the 70th calendar year after the author's death, whenever that may occur.
