In 1636 the city council of Leiden concluded an agreement with the organ builders Van Hagerbeer for the construction of a new organ. Over the years, this organ has been adapted to changing musical tastes. In the period 1943-46 an attempt was made to restore the organ to its original state. Over time, however, this restoration was subject to a lot of criticism, partly due to the ongoing historical research into 17th-century organ building. In the period 1994-1998 the organ was restored again. This restored a unique city organ from the Golden Age to its original glory. This organ is special in itself, because it is the largest organ in the world in meantone tuning. On the CD "Ars organorum Europea" organist Leo van Doeselaar charts various aspects of European organ culture of the 16th and 17th centuries. The program includes works by Sweelinck, Peter Philips, Abraham van den Kerckhoven, Anthoni van Noordt, Froberger and Scheidemann, among others.