Despite Messiaen's position as one of the greatest technical innovators of the twentieth century, his musical language has not been comprehensively defined and investigated. The composer's 1944 theoretical study, The Technique of My Musical Language, expounds only its initial stages, and while his posthumously published Traite de rythme, de couleur, et d'ornithologie contains detailed explanations of selected techniques, in most cases the reader is left to define these more precisely by observing them in the context of Messiaen's analyses of his own works. Technical processes are nevertheless in many cases the primary components of a work or movement. For instance, personnages dominate 'Joie du sang des etoiles' from the Turangalila-symphonie, and in certain cases, such as 'L'echange' from the Vingt regards sur l'Enfant-Jesus, the process (asymmetric augmentation) is the only structuring element present. Given this reliance on idiosyncratic techniques, clear comprehension of the music is impossible without a detailed knowledge of Messiaen's methods. Gareth Healey charts their development and interconnections, considers their relationship with formal structures, and applies them in refined and extended form to works for which Messiaen himself left no published analysis."
This is a very comprehensive compendium of Messiaen´s techniques. Sadly, the author spends pages, chapters, and indeed the whole book without providing convincing explanations or proper definitions. As an example, he writes extensively about "turning chords", only for us to learn, from the appendix, that the "harmonic origin of the chords is unclear, as is the logic of their ‘turning’".
Nonetheless, he embarks in very synthetic analysis that reads more like the report of a chemist than the findings of a musician. The prose is dry, musical examples (as opposed to convoluted, counterintuitive graphs) are scarce and unclear. While it is a good summary for those who already familiar with Messiaen´s music, this colourless, lifeless, and unkind book doesn't´t do it justice.