An example of the freer improvisation music from within the jazz tradition, as it began its development in the Netherlands in the 1960s. First the Heavy Soul Inc. quartet from saxophone player Hans Dulfer from 1968, followed by solo work by trombone player Willem van Manen from 1979.
Sources:
Hans Dulfer: The Formative Years (EMI box, disc 1)
Willem van Manen (BVHaast 027, collectors item)
