KDV means circle of barrel friends
The Circle of Barrel Friends is an association that is committed to arousing interest in the (Dutch) rotary organs and their preservation. KDV has been in existence since 1954 and gives a magazine for its members (the street organ) which appears 4 times a year. The KDV organizes barrel events in which one can get acquainted with the different types of rotary organs, the KDV also produces CDs with barrel music. The KDV also gives advice to Governments on matters related to the preservation or operation of rotary organs (think of permits, subsidy or housing of a museum).
How does a rotary organ work? [YouTube] W-YQKxW-P3U [/youtube]