Jonathan Janson maintains a wonderful site called essential vermeer, which is dedicated to the work and life of Dutch painting master, Vermeer. A fantastic resource in its own right, it also includes a section on folk music at the time of Vermeer, including a comprehensive essay by Adelheid Rech on the hurdy-gurdy. Beautifully illustrated with period paintings and well written, it is an excellent guide to the history of the instrument. Well worth a read. Online here.