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.
As long as the work was never copyrighted, has not fallen into the public domain and was created before January 1, 1978, on that date a statutory copyright automatically attached to the work for the authorâs life plus 70 years.