The êchoi belong to the Byzantine liturgical tradition; unlike the “modes” which were an abstract organization of scales, they were melodic formulas including the most salient characteristics (beginning, end, progressions) of a melody. Often called Octoechos, they were organized in groups of two. In an octophonic environment, the idea of eight echoes corresponding to melodic formulas that I interpret as objects, could not but seduce me. I added to this the definition of the characteristics of the nymph Echo, given by P. Commelin in his Greek and Roman Mythology where he tells us that "Ever...