The Japanese National Theater has a series called Nihon ongaku sōsho 日本音楽叢書 collecting essays from the programs of past stage productions into themed books. One of the books is called Reigaku 伶楽 (a neologism that basically means "contemporary works for gagaku ensemble"), and it contains an essay by Hosokawa Toshio about Tokyo 1985. It starts off with some discussion of lines, space and ma that I thought might be of interest to a couple of readers. Here's a quick and dirty translation because I have to go return the book now:

The line is a metaphor for a range of forms and lives, and a line that can be seen suggests a world that cannot. If the line did not exist, we could not see the shapes of things or sense the unseen world.

Could we not take the sound, too, as a line that is formed within the negative space that is the atmosphere? By replacing lines spatially with sounds, I came to think of the sound as like the line [...] in possessing an unseen, unheard matrix domain. [...] Sounds do not have meaning in and of themselves, but only recover their vitality by involvement with the place (topos) where they are created and the people in that place. In modern European music, interest has concentrated around the domain of sound as the result of an all-too-audible sound creation process and the domain of the visible écriture on the staff; the unseen, unheard domain of shadows has been discarded as part of this development.

The ma that is often spoken of in the context of traditional Japanese music is the tension-filled space-time from the void to the paper when creating a line; it is most certainly not a "silence" in the form of a vacuum of homogenous space from which meaning and direction have been stripped. It is a space dense and polysemous with meaning and directionality, a creative matrix space.

Hosokawa also has a note about that "silence" thing:

Since the 1983 premiere of my orchestral work Hi no kūkan 否の空間 [I think this must be the one known in English as "Pass into Silence" --Matt], I have released a number of works concerned with meaning-dense and directional "ma." However, partly due to the ambiguity of my vocabulary, my work has received from critics ambiguous labels such as "aesthetics of silence." What I thought of as "silence" is not a space that has lost meaning (R. Barthes), but a space inaudible to the ear as a densely meaningful place (topos) ; I realized this only after encountering several books by Nakamura Yujiro. After that, I began using the word "matrix space" instead of "silence" to describe this concept.