Our knowledge of the older period is derived from Church service books Typika, patristic writings and medieval histories. Scattered examples of hymn texts from the early centuries of Greek Christianity still exist. Two concepts must be understood if we are to appreciate fully the function of music in Byzantine worship. Most significant in the fact, outlined in Exodus 25, that the pattern for the earthly worship of Israel was derived from heaven. The allusion is perpetuated in the writings of the early Fathers, such as Clement of Rome, Justin, Ignatius of Antioch Athenagoras of Athens and Pseudo-Dionysios the Areopagite.
Angels Learn about the heavenly hosts that play an important role in Orthodoxy.