There is something very appealing and fundamental in music about the juxtaposition of two contrasting ideas. It seems to lie near the core of so much form, in both Western and Eastern music. It can occur at the microscopic level of the balanced motifs, phrase and answer, subject and countersubject, the expanding sets of bars in powers of two, chorus and verse, loosely called binary form. But it can also occur, as here, in the wider form of an unfolding alternation of mood.
I cannot help thinking of Ives with the hymn singing versus the thunderclaps in Hawthorne, the philosophical contrasts in the Celestial Railroad, the materialism against spirituality of his fourth symphony. I am confident this analogy is not misplaced. I thought I would not like this improvisation but I do, and I have listened to it a number of times so far.
The ordinary English meaning of chaos, in the sense of total disorder, is of course not at all what the mathematical study is about. That was a very unfortunate name to have given the science but it can hardly be retracted now. Yes Wolfi, I have a pet theory about mathematical chaos and improvisation which I might have discussed ages ago somewhere on the forum. I wasn't aware that somebody else had written about it.