In addition to the other rich comments already offered by friends of the forum, I would like to point out how something that may appear non-traditional at first glance can instead have references to tradition. A composer's ability is also shown in decontextualizing or “making one's own” (incorporating into one's own aesthetics) procedures that are already established or well-known.
In the past, I dealt with understanding why Bach, in the fugue BWV855, had inserted measures that proceeded in unison (see 19 and 38); in effect, there are solutions to avoid this procedure, which is somewhat un-contrapuntal or otherwise not quite typical of a fugue.
In my view, there is a very plausible reason that can be traced back to a certain “fashion” which was then consolidated by the Mannheim school, which carried forward one of Vivaldi's “legacies” (proceeding in unison often involved both choir and orchestra; that type of “gesturality” was quite popular... try to imagine the visual impact of an orchestra moving while playing the same notes).
Indeed, in the works of Vivaldi himself, such as Magnificat and Lauda Jerusalem (double choir), these procedures are evident... Bach, regarding BWV855, certainly underwent the influence of Vivaldi, and we know well how much he “transcribed” from his music.
In the fugue, the movement in octaves arrives in the form of intensification, just as occurred with the orchestral gesture (clearly, Bach uses other things to achieve this goal, but the “gesture” is also used for this purpose).
Thus, instead of “melody,” Simon Steen-Andersen uses sound; he does not use the gesture only to emphasize a possible intensification, but it becomes a constant in the piece, indeed the core element… in my opinion, in fact, an expert, even if not accustomed to this type of repertoire, cannot help but find these elements. In the end, the elements highlighted by Xenakis are very evident and perfectly placeable within a formal structure of a “classical” matrix. Of course, the Subjects/Themes change, as do the Materials and the technique of developing the material itself… but the piece presents all the characteristics of “the art and science of organizing sounds in time and space.” A very general definition of music, criticized but also very concrete and perhaps debatable because, in a few words, it encompasses the world, including the piece in question.
Then, as always, the musician's abilities can more or less keep attention alive, and I agree with Xenakis especially when he says that it drags on a bit. Surely Simon Steen-Andersen's approach was a choice, but either something should have happened at a certain point, or perhaps he could have started playing differently with the material. Certainly, in my opinion, there is a component of taste; I prefer the first material to the second, so I am sorry that he worked on the first in favor of the second, thinning it out until it almost disappeared. Let's just say I would have done the opposite…
I would also like to point out the extreme precision of the performers, their sensitivity in achieving very granular dynamic nuances, making simple instrumental gestures appear often complex… such as the passage indicated by Xenakis around 2'10''. Furthermore, the performers achieve perfect synchrony in the instrumental gesture even while being side-by-side... precisely “beside” each other (referring to the pun explained by Red). In short, without seeing each other directly.
On this aspect as well, however, I would have extended the synchrony to parts of the body not involved in the performance… the movement of the faces (rarely the expressions) is not synchronized. On one hand, this can be read as preserving one of the human aspects; I, on the other hand, would have appealed to robotics (or at least to “martiality”) to render what Red defines as “loop, irony, gesturality, abstract becoming concrete”… also “surreal.”
