Time's arrow in spectral music

Sonographic analysis offers composers of spectral music a wealth of scientific data regarding the internal and temporal structure of sound. Starting from these observations various techniques of instrumental synthesis have been elaborated, including sonogram simulation, ring modulation, frequency modulation, etc. These represent the basis of the spectral compositions of the Seventies. The grounding elements of the spectral attitude are based on one hand on the continuity of the acoustic field (from sine wave through various forms of harmonic and inharmonic spectra toward white noise) and, on the other, on the continuity of the fi eld of durations (from periodicity to the statistical distribution). Considering these perceptual points of orientation, the composers organize various transformational processes and by so doing they articulate the global form. The concept of directionality, abandoned during the integral serialism practice, is now restored thanks to the trajectories of transformational processes which shape the sound material in its restless becoming. Handling these trajectories from both the compositional and the perceptual point of view and inspired by Stockhausen’s “Veranderungsgrad”, Grisey theorizes the concept of pre-audibility. It refl ects the composers’ interest in the perceptual dimensions and in the role the difference plays in the processes of building both the local and macrostructural trajectories. In the early phase (Seventies and early Eighties) the spectral processes time’s arrow seems irreversible. However, the extreme slowness and predictability of sound becoming introduce some new challenges to composers. The concept of temporal scale is theorized and it acts as factor of new macroformal dynamics as well as new temporalities.