He wrote the pieces between 1900 and 1907, but they were not published until 1913. Whatever the reason for the delay (perhaps no other publisher would take them seriously?), Decaux’s teacher Massenet died in 1912 and so was spared what would surely have been a rude shock, not so much at the technique—as Richard Taruskin has pointed out, everything stems from the two falling bell motives at the outset (major second, major third; minor second, minor third)—as at the extraordinary harmonies and the no less extraordinary syntax. Whole tone aggregations (as at the beginning of ‘La Ruelle’) and consecutive fifths were nothing so out-of-the-way around 1900, but some of Decaux’s chords seem to have been taken from a source such as the songs in Schoenberg’s Das Buch der hängenden Gärten; the only problem being that these weren’t written until 1909. Throughout, major and minor triads are scrupulously avoided or else, as in ‘La mer’, coloured persistently with a sharpened fourth. Again, this piece was written in December 1903, nearly two years before the premiere of Debussy’s La mer and six years before his similarly wild Prélude ‘Ce qu’a vu le vent d’ouest’.
I'd say that's pretty interesting