The profile concept in Schaeffer‘s solfège: discussion of its diverse meanings and proposal of a quantitative real-time approach

In his Traité des Objets Musicaux (1966), Schaeffer proposes a solfège dedicated to any sound potentially musical, built upon seven perceptual criteria: mass, dynamic, harmonic timbre, melodic profile, mass profile, grain, allure. The practice of this solfège relies on reduced listening, a deconditioning attitude that focuses on the intrinsic properties of the sounds and ignores their origins or meanings. In two recent works, we have proposed a quantitative real-time interactive approach of five perceptive criteria, excluding the profiles, based on the assumption that the use of low-level descriptors has similarities with the practice of reduced listening. Our next step was to quantitatively tackle the two remaining criteria after understanding the scope of the term profile in the Schaefferian theory. We aim to use this tool in pedagogical and creative situations. Schaeffer almost always associates the term profile with a temporal variation of at least one sonic feature. Also, he usually connects this term with a sound object bearing an optimal duration for the memorization. Moreover, this temporal variation is expected not to be perceived as cyclic, in which case he prefers the term allure. Profiles are associated not only with the main criteria (dynamic profile, harmonic profile, melodic profile, mass profile) but also with second-order variations such as the speeding up of an allure, the gradual granulation of a sound, or even a "profiled" profile. We have adapted and developed a series of time-varying low-level descriptors used for the characterization of these criteria: temporal envelope, number of grains and allures, number of partials responsible for 50% and 80% of the total energy, presence, and estimation of the fundamental frequency, spectral centroid, intrinsic dissonance, spectral distribution. In the present work, we present the correlations found between some selected descriptors and the different types of profiles.