Sibley librarian Barbara Duncan purchased the manuscript for the sum of 30,000 francs from Parisian dealer Robert Legouix, whom Miss Duncan met at auction in Berlin in June 1929. The auction was the occasion of sale, by the firms of Martin Breslauer and Leo Piepmannssohn, of the personal library of German music collector and critic Dr. Werner Wolffheim (1877–1930), whose personal collection ranked as one of the most illustrious private collections of the day. (It was at that same auction that Miss Duncan acquired what would become yet another Sibley treasure, the so-called “Rochester” Codex.) Miss Duncan briefly described the circumstance in a letter (June 6th, 1929) to University of Rochester University Librarian Donald Gilchrist, sent from Berlin:
The dealers of course are all trying to sell me all sorts of things and are being so nice to me! But don’t worry I shan’t lose my head and they can’t sell me any thing I don’t want! Another thing to talk about I have bought of Legouix (that is I told him he must first have a letter from you confirming my order) that is a real treasure. The autograph of the first draft of Debussy’s “La Mer” his most important orchestral work after the “three nocturnes” which Carl Engel bought a few years ago. It is a beautiful mss. of twenty odd folio pages signed in full and dated at the end. Debussy is an outstanding figure in music (there is no doubt of that) he is an innovator and his manuscripts are most valuable. Legouix is selling this score and another of his for the heirs. The price is 1200 dollars (I have forgotten the francs).
… Good Heavens, the Frenchman [sic] is suspicious and nervous! Everything had to be in writing. Perhaps because he was a prisoner in Germany for over three years during the war is one reason why he is so sensitive. … Because he was so edgey [sic] I thought he had better have some connection with you so that if the bill should be delayed he would be able to write directly to you.
Since then, the manuscript has been the treasured showpiece of the Sibley Music Library’s holdings—truly the jewel in the Sibley crown.