DEUS EX MACHINA, UNCOVERING ALDO CLEMENTI’S SYSTEM 1 MICHELE ZACCAGNINI 1. INTRODUCTION TALIAN COMPOSER ALDO CLEMENTI, who passed away in 2011, has left us with a substantial oeuvre. Though not a household name in the contemporary music scene, he maintains the solid reputation of a composer who over the decades produced a highly idiosyncratic yet consistently reined oeuvre. 2 Clementi’s late period, usually identiied as the “diatonic period,” consists of a collection of sound panels built on simple, diatonic melodic fragments: Clementi . . . moved away from the structuralism of his early works towards a compositional method based on the selection and sub- sequent polyphonic elaboration of modal and diatonic materials drawn from past European music, particularly the music of Bach and Brahms, but also Stravinsky, Tchaikovsky, Liadov, Chopin, Schumann, Mozart, Purcell, Dufay, troubadour melodies and Gre- gorian chant. 3 I