«…une structuration plurielle de l’espace sonore». Assunti fondamentali ed esempi da “Par les rues et par les chemins” (Ibéria) di Claude Debussy

In Debussy’s Resonance (2018), the curators speak of an initial resistance posed by the composer’s singular style to the two major North American theoretical-analytical approaches: the Schenkerian and the set-theoretical ones. This resistance, however, is said to have encouraged the development of these theories themselves as well as other approaches: “a more liberal interpretation of Schenker’s ideas” elaborated by Adele Katz and Felix Salzer, which paved the way for more recent studies by Matthew Brown and Boyd Pomeroy; the extension of set theory promoted by Allen Forte himself and by Richard Parks, following Debussy’s exclusion from The Structure of Atonal Music; various contributions on the treatment of individual pitch collections and scales and on their interactions (Jean-Louis Leleu, Dmitri Tymoczko, Elliott Antokoletz). To these should be added an expansion of generative grammar, proposed by Fred Lerdahl (for “La terrasse des audiences du clair de lune”); one of Edward T. Cone’s theory of stratification, interlocking, and synthesis (Mark McFarland on “Ondine” and “Brouillards”); an application of David Lewin’s transformational theory (for “Feux d’artifices”); and other experiments from the neo-Riemannian galaxy. The present chapter does not go beyond this framework, but rather takes a position in relation to the theme of the volume in which it appears (post-tonal harmony and its analysis). The introduction legitimizes the chosen case study. The first part briefly presents assumptions derived from studies on early twentieth-century music that Jean-Louis Leleu has carried out over the last thirty years, with particular reference to those on Debussy. The second part interprets, on this basis, selected passages from the first movement of Ibéria (“Par les rues et par les chemins”), allowing readers to compare the results with the analyses previously undertaken by Pomeroy and Brown. The two American musicologists approach the entire work by commenting on their middleground graphs. This text, instead, analyzes mm. 1–40 and 178–203 starting from the score: it seeks to identify the logic of their harmonic succession, without necessarily reducing it to the notion of “extended tonality,” while instead considering the possibility that different systems or modes of pitch-space organization interact within it.