Byzantine music is the chanted prayer of the Orthodox Church left to us as a spiritual legacy by the holy masters of hymnography and hymnology ever since the early centuries. This music serves a precise purpose, i.e. to enhance the mood of prayer and to lift man closer to God. The Holy Liturgy, the mystical centre and the reference point of a man’s entire existence, represents man’s private meeting and communion with Christ, and the moment of this meeting is steeped in an atmosphere of meditation and inwardness created by a series of ample, slow, and vocalization-rich chants, called koinonika. It is a moment of ultimate inner appeasement and preparation. Early composers managed to capture this meditation effect in their koinonika, both through their compositional techniques and, especially, through an inner state of grace. However, in the 19th century, two phenomena became apparent: on the one hand, some of the new composers no longer succeeded in attaining the same ethos as the old masters, and, on the other hand (particularly from Ioan Popescu-Pasărea on), the music tastes of the time caused these ample chants to be replaced with simpler melodies, which, often, were even harmonized. This study has a threefold aim: first, it reasserts the fundamental role played by the koinonikon in the Holy Liturgy, by arguments that underline the ancientness of this practice as well as its survival in other Orthodox areas (such as Mount Athos and Greece). Second, the paper signals the publication, next year, of the first Romanian collection of koinonika signed by Byzantine and post-Byzantine composers (13th-19th centuries). Third, our study aims to show that these ancient chants have a special ethos, representing melodic as well as aesthetic archetypes and, par excellence, the true Classicism of Byzantine melos.