Three Modes Superposed
Definition: An expansion of polymodal technique to three simultaneous modal layers, creating highly complex vertical sonorities while maintaining the principle that each layer operates consistently within its assigned mode.
Messiaen's Treatment: Messiaen references Chapter VI, article 3, Example 43 ("l'Ange aux parfums"), which superposes three rhythmic pedals—the second being the retrograde of the first, the third being nonretrogradable. This example unites polyrhythm and polymodality, using Mode 2, first transposition in the upper staff; Mode 3, third transposition in the middle staff; and the whole-tone scale (Mode 1) in the lower staff. This last mode is transformed by the polymodal sonority, excusing its use, which is otherwise forbidden in Messiaen's language (as established in Chapter XVI).
Modern Context: Three-mode polymodality approaches chromatic saturation—the union of three distinct modal collections typically contains ten or eleven of the twelve available pitch classes, leaving little "outside" material. This creates extremely dense harmonic textures while maintaining theoretical distinction from free chromaticism through the systematic modal organization of each layer. The integration of polyrhythm with polymodality (as in Example 43) demonstrates Messiaen's holistic compositional approach where rhythmic and harmonic stratification reinforce each other—distinct temporal layers correlate with distinct pitch-class layers, creating multi-dimensional structural independence.
The "rehabilitation" of the whole-tone scale (Mode 1) through polymodal combination reveals an important principle: materials Messiaen considers overused or clichéd when employed in isolation can regain freshness and interest when embedded in more complex contexts. The polymodal sonority "transforms" or "excuses" the whole-tone scale's presence, suggesting that polymodality functions not merely as additive combination but as transformative interaction—the modes don't simply coexist but mutually modify each other's perceptual effect. Contemporary composers working with spectral techniques or complex harmonic fields would recognize similar phenomena where individual components contribute to emergent sonic properties not predictable from the isolated materials. The rarity of three-mode examples in the chapter (only one is cited) suggests that Messiaen found two-mode textures more practical or musically effective, reserving three-mode combinations for special coloristic effects or particularly dense passages.
Examples: Example 43 (Chapter VI)