Byzantine music

Byzantine music originally consisted of the songs and hymns composed for the courtly and religious ceremonial of the Byzantine Empire and continued, after the fall of Constantinople in 1453, in the traditions of the sung Byzantine chant of Eastern Orthodox liturgy. The ecclesiastical forms of Byzantine music are the best known forms today, because different Orthodox traditions still identify with the heritage of Byzantine music, when their cantors sing monodic chant out of the traditional chant books such as the Sticherarion, which in fact consisted of five books, and the Irmologion.
Byzantine music did not disappear after the fall of Constantinople. Its traditions continued under the Patriarch of Constantinople, who after the Ottoman conquest in 1453 was granted administrative responsibilities over all Eastern Orthodox Christians in the Ottoman Empire. During the decline of the Ottoman Empire in the 19th century, burgeoning splinter nations in the Balkans declared autonomy or autocephaly from the Patriarchate of Constantinople. The new self-declared patriarchates were independent nations defined by their religion.
In this context, Christian religious chant practiced in the Ottoman Empire, in, among other nations, Bulgaria, Serbia and Greece, was based on the historical roots of the art tracing back to the Byzantine Empire, while the music of the Patriarchate created during the Ottoman period was often regarded as "post-Byzantine." This explains why Byzantine music refers to several Orthodox Christian chant traditions of the Mediterranean and of the Caucasus practiced in recent history and even today, and this article cannot be limited to the music culture of the Byzantine past.
The Byzantine chant was added by UNESCO in 2019 to its list of Intangible Cultural Heritage "as a living art that has existed for almost 2,000 years, the Byzantine chant is a significant cultural tradition and comprehensive music system forming part of the common musical traditions that developed in the Byzantine Empire."

Imperial age

The tradition of eastern liturgical chant, encompassing the Greek-speaking world, developed even before the establishment of the new Roman capital, Constantinople, in 330 until its fall in 1453. Byzantine music was influenced by Hellenistic music traditions, classic Greek music as well as religious music traditions of Syriac and Hebrew cultures. The Byzantine system of octoechos, in which melodies were classified into eight modes, is specifically thought to have been exported from Syria, where it was known in the 6th century, before its legendary creation by Arab monk John of Damascus of the Umayyad Caliphate.
The term Byzantine music is sometimes associated with the medieval sacred chant of Christian Churches following the Constantinopolitan Rite. There is also an identification of "Byzantine music" with "Eastern Christian liturgical chant", which is due to certain monastic reforms, such as the Octoechos reform of the Quinisext Council and the later reforms of the Stoudios Monastery under its abbots Sabas and Theodore. The triodion created during the reform of Theodore was also soon translated into Slavonic, which required also the adaption of melodic models to the prosody of the language. Later, after the Patriarchate and Court had returned to Constantinople in 1261, the former cathedral rite was not continued, but replaced by a mixed rite, which used the Byzantine Round notation to integrate the former notations of the former chant books. This notation had developed within the book sticherarion created by the Stoudios Monastery, but it was used for the books of the cathedral rites written in a period after the fourth crusade, when the cathedral rite was already abandoned at Constantinople. It is being discussed that in the Narthex of the Hagia Sophia an organ was placed for use in secular processions of the Emperor's entourage.

The earliest sources and the tonal system of Byzantine music

According to the chant manual "Hagiopolites" of 16 church tones, the author of this treatise introduces a tonal system of 10 echoi. Nevertheless, both schools have in common a set of 4 octaves, each of them had a kyrios echos with the finalis on the degree V of the mode, and a plagios echos with the final note on the degree I. According to Latin theory, the resulting eight tones had been identified with the seven modes and tropes. The names of the tropes like "Dorian" etc. had been also used in Greek chant manuals, but the names Lydian and Phrygian for the octaves of devteros and tritos had been sometimes exchanged. The Ancient Greek harmonikai was a Hellenist reception of the Pythagorean education programme defined as mathemata. Harmonikai was one of them. Today, chanters of the Christian Orthodox churches identify with the heritage of Byzantine music whose earliest composers are remembered by name since the 5th century. Compositions had been related to them, but they must be reconstructed by notated sources which date centuries later. The melodic neume notation of Byzantine music developed late since the 10th century, with the exception of an earlier ekphonetic notation, interpunction signs used in lectionaries, but modal signatures for the eight echoi can already be found in fragments of monastic hymn books dating back to the 6th century.
Amid the rise of Christian civilization within Hellenism, many concepts of knowledge and education survived during the imperial age, when Christianity became the official religion. The Pythagorean sect and music as part of the four "cyclical exercises" that preceded the Latin quadrivium and science today based on mathematics, established mainly among Greeks in southern Italy. Greek anachoretes of the early Middle Ages did still follow this education. The Calabrian Cassiodorus founded Vivarium where he translated Greek texts, and John of Damascus who learnt Greek from a Calabrian monk Kosmas, a slave in the household of his privileged father at Damascus, mentioned mathematics as part of the speculative philosophy.
According to him philosophy was divided into theory and practice, and the Pythagorean heritage was part of the former, while only the ethic effects of music were relevant in practice. The mathematic science harmonics was usually not mixed with the concrete topics of a chant manual.
Nevertheless, Byzantine music is modal and entirely dependent on the Ancient Greek concept of harmonics. Its tonal system is based on a synthesis with ancient Greek models, but we have no sources left that explain to us how this synthesis was done. Carolingian cantors could mix the science of harmonics with a discussion of church tones, named after the ethnic names of the octave species and their transposition tropes, because they invented their own octoechos on the basis of the Byzantine one. But they made no use of earlier Pythagorean concepts that had been fundamental for Byzantine music, including:

Greek Reception	Latin Reception
the division of the tetrachord by three different intervals	the division by two different intervals
the temporary change of the genus	the official exclusion of the enharmonic and chromatic genus, although its use was rarely commented in a polemic way
the temporary change of the echos	a definitive classification according to one church tone
the temporary transposition	absonia, although it was known since Boethius' wing diagramme
the temporary change of the tone system	no alternative tone system, except the explanation of absonia
the use of at least three tone systems	the use of the systema teleion, relevance of Dasia system outside polyphony and of the triphonia mentioned in the Cassiodorus quotation unclear
the microtonal attraction of mobile degrees by fixed degrees of the mode and its melos, not of the tone system	the use of dieses, since Boethius until Guido of Arezzo's concept of mi

It is not evident by the sources, when exactly the position of the minor or half tone moved between the devteros and tritos. It seems that the fixed degrees became part of a new concept of the echos as melodic mode, after the echoi had been called by the ethnic names of the tropes.

Instruments within the Byzantine Empire

The 9th century Persian geographer Ibn Khurradadhbih ; in his lexicographical discussion of instruments cited the lyra as the typical instrument of the Byzantines along with the urghun, shilyani and the salandj.
The first of these, the early bowed stringed instrument known as the Byzantine lyra, would come to be called the lira da braccio, in Venice, where it is considered by many to have been the predecessor of the contemporary violin, which later flourished there. The bowed "lyra" is still played in former Byzantine regions, where it is known as the Politiki lyra in Greece, the Calabrian lira in Southern Italy, and the Lijerica in Dalmatia.
The second instrument, the Hydraulis, originated in the Hellenistic world and was used in the Hippodrome in Constantinople during races. A pipe organ with "great leaden pipes" was sent by the emperor Constantine V to Pepin the Short King of the Franks in 757. Pepin's son Charlemagne requested a similar organ for his chapel in Aachen in 812, beginning its establishment in Western church music. Despite this, the Byzantines never used pipe organs and kept the flute-sounding Hydraulis until the Fourth Crusade.
The final Byzantine instrument, the aulos, was a double-reeded woodwind like the modern oboe or Armenian duduk. Other forms include the plagiaulos, which resembled the flute, and the askaulos, a bagpipe. These bagpipes, also known as Dankiyo, had been played even in Roman times. Dio Chrysostom wrote in the 1st century of a contemporary sovereign who could play a pipe with his mouth as well as by tucking a bladder beneath his armpit. The bagpipes continued to be played throughout the empire's former realms down to the present.
Other commonly used instruments used in Byzantine Music include the Kanonaki, Oud, Laouto, rotta, Santouri, Toubeleki, Tambouras, Defi Tambourine, Çifteli, Lyre, Kithara, Psaltery, Saz, Floghera, Pithkiavli, Kavali, Seistron, Epigonion, Varviton, Crotala, Bowed Tambouras, Šargija, Monochord, Sambuca, Rhoptron, Koudounia, perhaps the Lavta and other instruments used before the 4th Crusade that are no longer played today. These instruments are unknown at this time.
In 2021, archaeologists discovered a flute with six holes dated back to the 4th and 5th centuries AD, in the Zerzevan Castle.
The Byzantine music had been heavily influenced by the Pythagorean music theory about the ratios of a single string as these are depicted in the above pictures: