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.
The presence of a date on the title page alone may identify books published prior to the mid-1800s as first editions. A matching date on the copyright page (or the back of the title page) often identifies a book published in the mid - to late 1800s as a first edition. After 1900, a number of publishers did not or currently do not put the date on the title page of their first editions.