Again conceived on the principle of the ground represented from the beginning of the piece by a descending ground bass on Greek rhythms, the score is, above all, the exploration of a particular modality: a mode combining the idea of the rising melodic mode and the Phrygian mode on an augmented fourth axis.
The two primary motifs are an incantatory melody, ornamented and descending, wrapping itself round the poles of this mode, and a motif of perfect or augmented fourths, a more rhythmic, dynamic motif (stemming from the ornamentation process of the first). Although the latter is treated canonically first and foremost, often creating an atmosphere of melodic whirling, the second is linked rather to writing echoing itself and in shifted rhythmic accentuations.
The horn, with its possibilities of extreme dynamics and large differences in sound colours according to the playing methods and register, allows for a particularly developed dialogue of timbres and often plays the role of several instruments at a time, the organ's various changes of timbre reinforcing this sensation.
Thierry Escaich
Translated by John Tyler Tuttle