Summary

Chapter III transforms an analytical observation from Chapter II into a comprehensive compositional technique. The added value method—augmenting rhythms through addition of small durational values rather than proportional multiplication—provides Messiaen with a systematic means of creating rhythmic complexity that resists metric regularity while maintaining precise organization. The chapter's significance extends beyond the specific technique: it demonstrates Messiaen's method of parametric analogy (connecting rhythmic and harmonic domains), his integration of prime-number groupings with added values, and his conception of rhythm as possessing gestural shapes (preparations, accents, descents) parallel to melodic structures. The added value technique becomes one of Messiaen's most recognizable innovations, influencing subsequent generations of composers and establishing a model for non-proportional rhythmic transformation.

For contemporary readers, the chapter illustrates how systematic compositional thinking can generate rich musical surfaces from simple operational principles—adding small values creates metric ambiguity, temporal elasticity, and rhythmic character that distinguishes Messiaen's music from both metric regularity and unmeasured freedom.