What about the notes the composer wrote on the page? "I have been criticised for saying something like this; butI still. believe it:...

Very interesting section added, after I found an article by JB in Etude, November 1951. Once you are on your way, artistic abstractions...

An interview with the Leidsch Dagblad  (5 December, 1983) became quite animated. There was a big feature, with Charles van der Leeuw...