Organ music

I give up - neither in books nor in google can I find any information about organ music in Belgium! All that I have at the moment is Cathedral in Antwerpen, but even there hours of mass with organ and visiting hours do not match,which most likely means that organ masses are not open to the public :(
(link for myself: http://www.dekathedraal.be/en/bezoek.htm)

So, if anybody has any information about regular organ masses or concerts, or anything similar, where we can bring kids, PLEASE let me know! We are based in Ostend, but looks like with the trains everything is about an hour away. If not the train, we will just get a car, not a big deal.                    

And yes, I still can read in russian, just can't write in it at the moment :)