Debussy wanted to distance himself from what he considered the emotional excess of the Romantics and instead wanted to write music that, through sound, created an ambience similar to that of the Impressionist painters and Symbolist poets of his day.
All books initially copyrighted in the US from 1964 through 1977 have had their copyrights automatically renewed (by law) and the copyrights are still in force. The initial copyright term was 28 years; the renewal was for 67 more years.
Next, the copyright owner has a decision whether or not they want to formally copyright the work with the Copyright Office. You can register literary works with the form TX. The copyright owner can publish the book at a much later date. Publication isnât required for a work to be eligible for copyright protection.