Studying and the analysis of different schools of the Georgian church chanting enable to specify features of musical tradition of the Georgian church chanting. These traditions connect as laws of the Orthodox Church chanting, also historically combined structurally-composite rules of the Georgian church chanting. The article represents the scheme of eight-tuned church chanting. The structurally-composite structure which basis is the part of a piece of song is shown. Types of parts from the functional point of view are considered. On an example of several voices the principle of stability of parities of moduses of the melodic formulas is shown. The given principle in the eight-tuned system is based on the established structural laws. Comparison of examples of identity and at the same time alternativeness of melodic intonation of different schools Georgian multi-tuned church chanting gives an opportunity to reveal a melody-basis of the Georgian church chanting.