Spectral Composition

Physics: Spectral music (Grisey, Murail, 1970s–): derive pitch materials from acoustic analysis of real sounds. Grisey's "Partiels" (1975): entire chord derived from spectral analysis of a trombone E2 (82 Hz). Low pitches have dense harmonic content; high pitches are sparse. Spectral harmony = tuning to minimize beating (constructive interference). Ring modulation: output = f₁±f₂, creating sum and difference tones. IRCAM pioneered analysis-synthesis tools. The spectral centroid correlates with perceived brightness.