Hans Jenny's Cymatics is "dedicated to the memory of Rudolf Steiner, the Austrian founder of the anthroposophic school of mystical thought, and Jenny's work turns up in a Steiner-published book by Theodor Schwenk, Sensitive Chaos"
"a study of flow motion in water, air, and clouds"
Toop: "a 1960s precursor to the chaos maths fractals of the 1980s, Sensitive Chaos recalls the exhortations of John Cage, Pauline Oliveros or Roland Kirk to listen (without prejudice)"