The letter seems to me so obviously offensive that I can't help wonder if it's actually some sort of satirical parody. Tallying the many problems with its argument is left as an exercise to the reader.
My heartfelt thanks to Lothar Bandermann for his great letter regarding dissonant organ music. My definition of "dissonant" is music that I never want to hear again, and wish I had not heard the first time. I, too, have walked out of organ concerts because of "music" that is totally unpleasant to hear. I have a three-year-old grandson who can press on keys to make the organ do what some call music.
I love great organ music, and never tire of listening to great compositions. We all know what pleasant organ music is, and that is what the vast majority of listeners enjoy. If we can't wait for the piece to end, and can't tell if a wrong note is played, that is a perfect example of "dissonant." Would a non-musical person ever want to return to another organ program after listening to an organ concert where dissonant music is played? I think not. Just because a selection is written by a well-known composer doesn't mean it is good. Some is very unlistenable.
At our facility, we provide weekly pipe organ concerts in the summer, and I request that dissonant music not be played. That is the reason that we have an overflowing attendance at our programs. The listeners really like the music!
If we want to attract the average person to organ concerts, organists need to play what listeners like, not what the organist necessarily likes. If an organist wants to play dissonant selections, then he/she should do it in practice or at home where no one can hear.
It doesn't take a rocket scientist to know what enjoyable music is. Let's get with the program and play wonderful, fulfilling music, and attract more listeners who will be glad they spent an hour or so at an organ concert!