The piece begins with solo tape— a delicate, sparse texture created with several tracks of antique cymbals (I removed the attack part of the sound, leaving only the resonance).  I created the evolution of density and intensity in the pitched sections with fast, repeated note groups that slowly break off into separate streams.  Each cycle of the piece consists of an entirely pitched or unpitched section, and the cycles alternate between pitched and unpitched sections.  At the 8-min point, the second cycle of the pitched section begins.  Fast, repeated note groups (Fig.3) begin at seven or eight notes per second, with the note groups in each part playing pitches within a close frequency range, and all within the frequency span of an octave.  As the instruments play note groups of varying speed within the same frequency range, a series of interference patterns is produced, which creates the perception of a large, two-dimensional (2D) field.  The note groups slowly expand into a wider range and reach maximum density, intensity and volume (Fig.4) at the 12-min point.  The combination of note groups and timbres then create interference patterns with maximum intensity and the fast repeated note groups blur into frequency ranges; the frequency ranges begin to separate into streams.  Once the frequency ranges breaks down into separate streams, there is a complete loss of a sense of structured time; each of the percussionists plays note groups as quickly as possible while created a large 2D sound field where individual elements cannot be isolated.  The music moves out of a linear sense of time progression and into a large sound field, or texture.

Fig.3.  In this excerpt of Of Radiant Streams (1985), the fast, repeated note groups played by four mallet instruments result in interference patterns and auditory pitch segregation, or “streaming.”