Too bad Wim Magre has spasms in his hands when holding long notes. And by the way, Jan Zwart's son was the organist in this church for many, many years and without a doubt that first piece was played more than once on this organ. His son also had spasms in his hands, just like a whole generation of organists in Holland. It makes the organ sound wind sick. Too bad.
I had two organ builders at my house the other day. One local one and the other from the east coast. They were there at my invitation to have a listen to and play my Hauptwerk setup. They absolutely loved it and just didn't want to leave. I also showed them the DVD from Kampen which the above mentioned clip comes from and they both reckoned it was magic! They just couldn't stop talking about it. They had never seen or heard anything like it before and one of them said "It shows that the organ is really a masculine instrument when you can really work it like that and make it play the way you feel" or words to that effect. By varying the wind going to the pipes with your fingers in that way, you let your emotions show in the music. Have you ever seen a violin player not do the vibrato trick with his fingers? If they didn't do that there would be no warmth in the sound.
It is a shame that there is so much animosity between the Zwart/Asma school and the other Dutch organists and even more of a shame to have those feelings spill over onto a wonderful forum such as this. We are all entitled to our opinions but we shouldn't brand others as being wrong in their style when it is so obvious that they really have many fans in the Netherlands and overseas. As I mentioned on another post - One person calls it wind sick and another says that it makes the organ sing.