Since the very beginning of my research I had trouble modeling
silence. The silence is not just another pitch which has the
ability of not to sound. I think that silence has to be treated
apart from pitches, but I don't know how.
A question is "in what way is silence an event in the way pitch is an
event?"
Consider that musical events are always durational events (which poses
a philosophical problem as to whether the feeling someone gets from
music is necessarily durational). Qualitatively, musical silence is
(or can be) a kind of echoic extending of the last thing heard -- as
in a big crash before a long silence, with the crash still in echoic
memory. So silence is best seen not as "nothing" but rather as a
durational extension of a preceding sounding event. Rather than
theorizing silence, then, you need to theorize duration.
In computational composing, as I practice it -- see below -- duration
is the minimal & principle thing theorized. A collection of pitches
can be surmised as having a single duration when we can surmise the
likelihood of perceptual grouping. For example a fast scale ending on
an accented long note will tend to be grouped as a single event -- it
is a "shape." With these you make bigger shapes, until you can work
out that you have made a whole piece. In my work, "shapes" recursively
form part of macro-structural systems called "supershapes."
Nothing in music is ever an end in itself -- with duration (of shape,
of pattern of shapes, etc.) you can construct new rhythms and
patterns. You can construct patterns of "silence" just as you can
construct "the pattern of recurrence of the main theme or any of its
transformations." It may be a component of a rhythm or pattern of
rhythms, etc. Since the perception depends on whatever shapes come
forward to the listener -- which bigger components we are in -- it is
wrong to surmise that "silence" or "longness" are necessarily phrase
demarcaters. How they function would tend to be determined by the
music itself.
-- eliot
http://www.colba.net/~eliot/shape_web.html