This is the free "Zurek organ" version 4, a composite of several free demo sets from Jiri Zurek (Sonus Paradisi). This sample set is currently being developed by Anton Heger in discussion with members of the pcorgan.nl forum. See http://www.pcorgel.nl/viewtopic.php?f=6&t=1404
for information (in Dutch) and download links. After installing, some stops need to be tuned and voiced. A version 5 is upcoming.
This spontaneous improvisation features the reeds and demonstrates the dynamic range.