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 [[
Nicolas 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.
The second, less permanent, concept was that of ''koinonia'' or "communion." This was less permanent because, after the fourth century, when it was analyzed and integrated into a theological system, the bond and "oneness" that united the [[clergy]] and the [[laity|faithful]] in liturgical worship was less potent. It is, however, one of the key ideas for understanding a number of realities for which we now have different names. With regard to musical performance, this concept of koinonia may be applied to the primitive use of the word choros. It referred, not to a separate group within the congregation entrusted with musical responsibilities, but to the congregation as a whole. St. Ignatius of Antioch wrote to the Church in Ephesus [http://www.ccel.org/ccel/richardson/fathers.vi.ii.iii.i.html] in the following way:
:"''You must every man of you join in a choir so that being harmonious and in concord and taking the keynote of God in unison, you may sing with one voice through [[Jesus Christ]] to the Father, so that He may hear you and through your good deeds recognize that you are parts of His Son.''"
With the end of creative poetical composition, Byzantine chant entered its final period, devoted largely to the production of more elaborate musical settings of the traditional texts: either embellishments of the earlier simpler melodies, or original music in highly ornamental style. This was the work of the so-called ''Maistores'', "masters," of whom the most celebrated was St. [[John Koukouzeles]] (active ca. 1300), compared in Byzantine writings to St. John of Damascus himself, as an innovator in the development of chant. The multiplication of new settings and elaborations of the old continued in the centuries following the [[Fall of Constantinople]], until by the end of the eighteenth century the original musical repertory of the medieval musical manuscripts had been quite replaced by later compositions, and even the basic model system had undergone profound modification.
[[Chrysanthos of Madytos]] (ca. 1770-1846), [[Gregory the Protopsaltes]], and [[Chourmouzios the Archivist]] were responsible for a much needed reform of the notation of Greek ecclesiastical music. Essentially, this work consisted of a simplification of the Byzantine musical symbols which, by the early 19th century, had become so complex and technical that only highly skilled chanters were able to interpret them correctly. Despite its numerous shortcomings the work of the three reformers is a landmark in the history of Greek Church music, since it introduced the system of neo-Byzantine music upon which are based the present-day chants of the Greek Orthodox Church.
The current usage of Byzantine
chant is built upon eight modes (tones), each mode with its own specific tonality. The modes change sequentially from week to week, starting the Monday after the [[Sunday of St. Thomas]], with mode 1. Within [[Bright Week]] itself, the mode changes each day, thus: :Sunday – mode 1, :Monday – mode 2, :Tuesday – mode 3, :Wednesday – mode 4, :Thursday – mode plagal of the first (5), :Friday – mode plagal of the second (6), :Saturday – mode plagal of the fourth (8).
grave mode (7) was chosen as the mode to be left out due to its heavier sound, considered least appropriate for the festal period among the eight modes. Since [[ Pentecost]] falls on the Sunday when the grave mode would have been used in the normal sequence, the mode is once again skipped and the hymns of Pentecost are used. The sequence resumes the following week with plagal of the fourth.
In the time between a [[Great Feasts|great feast]] and its [[Leavetaking|leave-taking]], for example, during the week following Pentecost, the hymns of the feast are chanted rather than the hymns pertaining to the mode of the week.
*[http://www.ecclesia.gr/Multimedia/Audio_index/audioindex_en.html Ecclesia] The chanting page of the official website of the Church of Greece
*[http://www.kelfar.net/orthodoxiaradio/ Orthodoxia Radio] - Source for information and recordings of Byzantine chant as sung in the Church of Antioch
jamilsamara. com/ sacredmusic/ music.asp Sacred Music (Orthodox Liturgical Music)] - Official Antiochian Archdiocese site for free music downloads, including many Byzantine chant
*[http://chant.hchc.edu/ Learn Byzantine Chant] - A simplistic flash presentation from the [[Holy Cross Greek Orthodox School of Theology (Brookline, Massachusetts)|Holy Cross Greek Orthodox School of Theology]]