Key Concepts

This chapter introduces five key formal approaches adapted to Messiaen's compositional system:

1. Fugue: Episode and Stretto - Traditional contrapuntal form with episode (harmonic progression concealed by canonic imitation) and stretto (overlapping entries) adapted to modal contexts

2. Sonata-Allegro: Terminal Development - Traditional sonata form with recapitulation declared obsolete, emphasizing terminal development as essential formal principle

3. Development of Three Themes, Preparing a Final Issued from the First - Teleological form presenting three themes in condensed exposition, developing them toward climactic final statement derived from the first theme

4. Variations of the First Theme, Separated by Developments of the Second - Rondo-like structure alternating theme variations with developmental episodes, creating sophisticated interaction between variation and development principles

5. Plainchant Forms: Anthems, Alleluias, Psalmodics, Kyrie, Sequence - Large-scale formal structures derived from Catholic liturgical chant genres, providing models embodying centuries of sacred practice