Two concepts must be understood if we are to appreciate fully the function of music in Byzantine worship. The first, which retained currency in Greek theological and mystical speculation until the dissolution of the empire, was the belief in the [[angel]]ic transmission of sacred chant: the assumption that the early Church united men in the [[prayer]] of the angelic choirs. This notion is certainly older than the [[Apocalypse]] account ([[Book of Revelation|Revelation]] 4:8-11), for the musical function of angels as conceived in the [[Old Testament]] is brought out clearly by [[Book of Isaiah|Isaiah]] (6:1-4) and [[Book of Ezekiel|Ezekiel]] (3:12). 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 [[Church Fathers]], such as [[Clement of Rome]], [[Justin Martyr|Justin]], [[Ignatius of Antioch]], [[Athenagoras of Athens]], and [[Dionysius the Areopagite]]. It receives acknowledgement later in the liturgical treatises of [[Nicholas Cabasilas]] and [[Symeon of Thessaloniki]] (''Patrologia Graeca'', CL, 368-492 and CLV, 536-699, respectively).
The effect that this concept had on church music was threefold: first, it bred a highly conservative attitude to musical composition; second, it stabilized the melodic tradition of certain hymns; and third, it continued, for a time, the anonymity of the composer. For if a chant is of heavenly origin, then the acknowledgement received by man in transmitting it to posterity ought to be minimal. This is especially true when he deals with hymns which were
known to have been first sung by angelic choirs—such as the [[Amen]], [[Alleluia]], [[Trisagion]], [[Sanctus]], and [[Doxology]]. Consequently, until Palaeologan times, it was inconceivable for a composer to place his name beside a notated text in the manuscripts.
Ideas of originality and free invention similar to those seen in later music probably never existed in early Byzantine times. The very notion of using traditional formulas (or melody-types) as a compositional technique shows an archaic concept in liturgical chant, and is quite the opposite of free, original creation. It seems evident that the chants of the Byzantine repertory found in musical manuscripts from the tenth century to the time of the [[Fourth Crusade]] (1204-1261), represent the final and only surviving stage of an evolution, the beginnings of which go back at least to the sixth century and possibly even to the chant of the [[Synagogue]]. What exact changes took place in the music during the formative stage is difficult to say; but certain chants in use even today exhibit characteristics which may throw light on the subject. These include recitation formulas, melody-types, and standard phrases that are clearly evident in the folk music and other traditional music of various cultures of the East, including the music of the Jews.