Shedding more light on the subject is author Richard Z. Chesnoff, who detailed the Nazi’s wartime assault on French music & musicians in his 2001 book, 'Pack of Thieves: How Hitler & Europe Plundered the Jews and Committed the Greatest Theft in History':
“Nor was music immune from the Nazi’s reach. In August of 1940, just a month after Reichsleiter Rosenberg had established the first ERR office in Paris, a special Sonderstab Musik division of his operation was opened under the direction of Haupstellenleiter Herbert Gerigk. Its assigned task: to confiscate ancient French musical manuscripts as well as anything connected to music that belonged to Jews—instruments, books, scores, and recordings. Berlin’s instructions to Gerigk were “to process music literature, music paraphernalia, and music manuscripts … and … to prepare them for shipment to Berlin, Leipzig, and Upper Bavaria.
The Sonderstab Musik raids on apartments in Paris and homes in the countryside, many of them abandoned or sealed, swept up not only pianos, violins, and other instruments belonging to individual Jewish families but also the personal collections of such international musical luminaries as Wanda Landowska, Darius Milhaud, and Arthur Rubinstein. A special series of music warehouses was established in Paris and equipped for storage and inventory of the instruments prior to their shipment to Germany. Three of the warehouses were devoted only to pianos. Another, on the rue Bassano ,was expressly created to house ‘small instruments.’
It was an enormous, if evil, task. According to a comprehensive study of Sonderstab Musik by Amsterdam University’s Willem de Vries, 1.500 workers were employed at the height of the Musik Aktion just to empty the ones of musically inclined French Jews. An average of two loot-laden trains departed for Germany each week—and at least one freight car in each shipment was loaded with musical instruments, gramophones, and music books.”