This composer plays the Rudolf-Knol organ in Hasselt for 40 years. This orgel is very know in the Netherlands due the famous sound. This organ is more windsick than the Hinz in Kampen. Based on this organ and the big acoustic of the church the composer made an improvisation about Psalm 68. Played for you on Metz.
For more information about the organ an audio examples see: http://www.knolorgelhasselt.nl