I vaguely remember Steven Johnson talking about the patterns in Feldman's Why Patterns when I was in his 20th century history class back in 2007. Yesterday I came across the collection of essays he edited,The New York Schools of Music and Visual Arts, and was happily surprised to see that the volume ends with his essay "Jasper Johns and Morton Feldman: What Patterns?" I haven't finished it yet, but the description of patterns in Johns's cross-hatch painting Usuyuki stopped me in my tracks. I'll paraphrase Johnson's description (using a different painting from the same series) and show a variation on an example in his book.
Usuyuki is good example of stasis through motion. It appears kind of all-over, random, on the surface, but on a larger level it moves downward as it moves left to right (I assume you can see the division of the work into 3 panels, and each panel into 9 self-contained blocks). What I find especially interesting is that the system (it's not at all random) is not restricted to the visible portion of the work. Or a better way of putting it is the system includes content that will never be seen by the viewer. Of course blocks A-F will eventually show up in the second and third panels, but they actually exist as part of the concept in the first panel where they are not seen.
Last spring I wrote a piece called Don't cross the streams for solo horn and computer music that is based on the idea of multiple "streams" happening simultaneously despite the fact that the horn meanders among these, and only one "stream" is heard at any point in time.
I'm reminded of a criticism of Ligeti's music along the lines of Why write such intricate and systematic canons when they will never be audible in the texture. So why create something that will never be seen or heard? This gets me to the Void, an idea that deeply informs my aesthetic.
The void as I understand it comes primarily from Seyyed Hossein Nasr's writings on Sufism, or Islamic mysticism. He summarized it this way: "…[T]he void, or that which is empty of things becomes a trace and an echo of God in the created order, for through its very negation of ‘things’ it points to that which is above and beyond all things. The void, therefore, is the symbol of both the transcendence of God and His presence in all things" (Islamic Art and Spirituality, 186). This is one explanation of aniconism in Islamic art, which moved Islamic art toward abstractions centuries before Western modernism. But, the concept of the trace and echo resonate with me. Negation, inversion, etc. are profound ways of pointing directly at something. Those inaudible or invisible parts of a system (the "created order") are echoed by the audible and visible parts. They are often crucial to a complete understanding of a work of music or art.