The author sees the distinctive mark of the Byzantine Church music in its fitting expression of the Orthodox theology, namely inthe equilibrium between its cataphatic aspect (the chanted text) and its apophatic aspect (the peculiar accompanishment, »isokratima«).

The monodic chant existed already in the Old Testament (with instrumental music), as now in the Roman Catholc Church singing — but only Orthodox Catholic Church — in her traditional Byzantine liturgical chant — has its musical basis in the inscrutable depth — in the apophatic »isokratima«„