paragraph_text: The key characteristic of classical music that distinguishes it from popular music and folk music is that the repertoire tends to be written down in musical notation, creating a musical part or score. This score typically determines details of rhythm, pitch, and, where two or more musicians (whether singers or instrumentalists) are involved, how the various parts are coordinated. The written quality of the music has enabled a high level of complexity within them: J.S. Bach's fugues, for instance, achieve a remarkable marriage of boldly distinctive melodic lines weaving in counterpoint yet creating a coherent harmonic logic that would be impossible in the heat of live improvisation. The use of written notation also preserves a record of the works and enables Classical musicians to perform music from many centuries ago. Musical notation enables 2000s-era performers to sing a choral work from the 1300s Renaissance era or a 1700s Baroque concerto with many of the features of the music (the melodies, lyrics, forms, and rhythms) being reproduced.

paragraph_text: The main representatives of the new style, often referred to as ars nova as opposed to the ars antiqua, were the composers Philippe de Vitry and Guillaume de Machaut. In Italy, where the Provençal troubadours had also found refuge, the corresponding period goes under the name of trecento, and the leading composers were Giovanni da Cascia, Jacopo da Bologna and Francesco Landini. Prominent reformer of Orthodox Church music from the first half of 14th century was John Kukuzelis; he also introduced a system of notation widely used in the Balkans in the following centuries.

paragraph_text: Bleda died in 445, with some historians speculating that his death was at the hands of Attila. With his brother gone, Attila was able to establish undisputed control over his subjects. In 447, Attila turned the Huns back toward the Eastern Roman Empire once more. His invasion of the Balkans and Thrace was devastating. The Eastern Roman Empire was already beset by internal problems, such as famine and plague, as well as riots and a series of earthquakes in Constantinople itself. A last - minute rebuilding of its walls preserved Constantinople unscathed. Victory over a Roman army left the Huns virtually unchallenged in Eastern Roman lands and they raided as far south as Thermopylae. Only disease forced them to retreat, and the war came to an end in 449 with an agreement in which the Romans agreed to pay Attila an annual tribute of 2100 pounds of gold. Our only first - hand account of conditions among the Huns and of Attila himself is by Priscus, an official in the peace embassy to Attila.

paragraph_text: Depopulation, deurbanisation, invasion, and movement of peoples, which had begun in Late Antiquity, continued in the Early Middle Ages. The barbarian invaders, including various Germanic peoples, formed new kingdoms in what remained of the Western Roman Empire. In the 7th century, North Africa and the Middle East—once part of the Eastern Roman Empire—came under the rule of the Caliphate, an Islamic empire, after conquest by Muhammad's successors. Although there were substantial changes in society and political structures, the break with Antiquity was not complete. The still-sizeable Byzantine Empire survived in the east and remained a major power. The empire's law code, the Code of Justinian, was rediscovered in Northern Italy in 1070 and became widely admired later in the Middle Ages. In the West, most kingdoms incorporated the few extant Roman institutions. Monasteries were founded as campaigns to Christianise pagan Europe continued. The Franks, under the Carolingian dynasty, briefly established the Carolingian Empire during the later 8th and early 9th century. It covered much of Western Europe, but later succumbed to the pressures of internal civil wars combined with external invasions—Vikings from the north, Magyars from the east, and Saracens from the south.

paragraph_text: On the continent of Europe, Anno Domini was introduced as the era of choice of the Carolingian Renaissance by the English cleric and scholar Alcuin in the late eighth century. Its endorsement by Emperor Charlemagne and his successors popularizing the use of the epoch and spreading it throughout the Carolingian Empire ultimately lies at the core of the system's prevalence. According to the Catholic Encyclopedia, popes continued to date documents according to regnal years for some time, but usage of AD gradually became more common in Roman Catholic countries from the 11th to the 14th centuries. In 1422, Portugal became the last Western European country to switch to the system begun by Dionysius. Eastern Orthodox countries only began to adopt AD instead of the Byzantine calendar in 1700 when Russia did so, with others adopting it in the 19th and 20th centuries.

paragraph_text: Surena or Suren, also known as Rustaham Suren (died 53 BC) was a Parthian "spahbed" ("general" or "commander") during the 1st century BC. He was the leader of the House of Suren and was best known for defeating the Romans in the Battle of Carrhae. Under his command Parthians decisively defeated a numerically superior Roman invasion force under the command of Marcus Licinius Crassus. It is commonly seen as one of the earliest and most important battles between the Roman and Parthian empires and one of the most crushing defeats in Roman history.

paragraph_text: Burgh (2006), suggests that the roots of Western classical music ultimately lie in ancient Egyptian art music via cheironomy and the ancient Egyptian orchestra, which dates to 2695 BC. This was followed by early Christian liturgical music, which itself dates back to the Ancient Greeks[citation needed]. The development of individual tones and scales was made by ancient Greeks such as Aristoxenus and Pythagoras. Pythagoras created a tuning system and helped to codify musical notation. Ancient Greek instruments such as the aulos (a reed instrument) and the lyre (a stringed instrument similar to a small harp) eventually led to the modern-day instruments of a classical orchestra. The antecedent to the early period was the era of ancient music before the fall of the Roman Empire (476 AD). Very little music survives from this time, most of it from ancient Greece.

paragraph_text: Middle C (the fourth C key from left on a standard 88 - key piano keyboard) is designated C in scientific pitch notation, the most commonly recognized in auditory science, while both C and the Helmholtz designation c 'are used in musical studies. Other note - octave systems, including those used by some makers of digital music keyboards, may refer to Middle C differently. In MIDI, Middle C is note number 60.

paragraph_text: Easter was the Sunday after the 15th day of this moon, whose 14th day was allowed to precede the equinox. Where the two systems produced different dates there was generally a compromise so that both churches were able to celebrate on the same day. By the 10th century all churches (except some on the eastern border of the Byzantine Empire) had adopted the Alexandrian Easter, which still placed the vernal equinox on 21 March, although Bede had already noted its drift in 725—it had drifted even further by the 16th century.

paragraph_text: The Gallic Empire () or the Gallic Roman Empire are names used in modern historiography for a breakaway part of the Roman Empire that functioned "de facto" as a separate state from 260 to 274. It originated during the Crisis of the Third Century, when a series of Roman military leaders and aristocrats declared themselves emperors and took control of Gaul and adjacent provinces without attempting to conquer Italy or otherwise seize the central Roman administrative apparatus.

paragraph_text: In the late 14th century, the Songhai gradually gained independence from the Mali Empire and expanded, ultimately subsuming the entire eastern portion of the Mali Empire. The Songhai Empire's eventual collapse was largely the result of a Moroccan invasion in 1591, under the command of Judar Pasha. The fall of the Songhai Empire marked the end of the region's role as a trading crossroads. Following the establishment of sea routes by the European powers, the trans-Saharan trade routes lost significance.

paragraph_text: Trowulan is an archaeological site in Trowulan Subdistrict, Mojokerto Regency, in the Indonesian province of East Java. It includes approximately 100 square kilometres and has been theorized to be the site of the eponymous capital city of the Majapahit Empire, which is described by Mpu Prapanca in the 14th-century poem Nagarakretagama and in a 15th-century Chinese source. When it was the capital of the Majapahit Empire, the city was known as Wilwatikta, which is a name also synonymous with the empire's name. It was razed during the invasion of Girindrawardhana to defeat Kertabhumi in 1478. After this event Majapahit's capital was moved to Daha (Kediri). The Trowulan Museum includes a collection of artifacts.

paragraph_text: Using his own system, Hampartsoum Limondjian transcribed most of 18th century Turkish music compositions in a collection of six books, which he presented to Selim III. Only two of the originals survive to date and are preserved at the Istanbul Municipal Conservatory Library. As the dominant notation for Turkish and Armenian music, the Hamparsum notation was instrumental in the transcription and survival of thousands of pieces of music, and was surpassed only in modern times in its use for Turkish classical music. The notation system is still in use by the Armenian Apostolic Church.

paragraph_text: The Valens Aqueduct ( or "Bozdoğan Kemeri", meaning "Aqueduct of the Grey Falcon"; , "Agōgós tou hýdatos", meaning simply "aqueduct") is a Roman aqueduct which was the major water-providing system of the Eastern Roman capital of Constantinople (modern Istanbul, Turkey). Completed by Roman Emperor Valens in the late 4th century AD, it was maintained and used by the Byzantines and later the Ottomans, and remains one of the most important landmarks of the city.

paragraph_text: By the end of the Western Roman Empire, the town was known simply as Parisius in Latin and Paris in French. Christianity was introduced in the middle of the 3rd century AD. According to tradition, it was brought by Saint Denis, the first Bishop of Paris. When he refused to renounce his faith, he was beheaded on the hill which became known as the "Mountain of Martyrs" (Mons Martyrum), eventually "Montmartre". His burial place became an important religious shrine; the Basilica of Saint-Denis was built there and became the burial place of the French Kings.

paragraph_text: As Western Europe witnessed the formation of new kingdoms, the Eastern Roman Empire remained intact and experienced an economic revival that lasted into the early 7th century. There were fewer invasions of the eastern section of the empire; most occurred in the Balkans. Peace with Persia, the traditional enemy of Rome, lasted throughout most of the 5th century. The Eastern Empire was marked by closer relations between the political state and Christian Church, with doctrinal matters assuming an importance in eastern politics that they did not have in Western Europe. Legal developments included the codification of Roman law; the first effort—the Theodosian Code—was completed in 438. Under Emperor Justinian (r. 527–565), another compilation took place—the Corpus Juris Civilis. Justinian also oversaw the construction of the Hagia Sophia in Constantinople and the reconquest of North Africa from the Vandals and Italy from the Ostrogoths, under Belisarius (d. 565). The conquest of Italy was not complete, as a deadly outbreak of plague in 542 led to the rest of Justinian's reign concentrating on defensive measures rather than further conquests. At the emperor's death, the Byzantines had control of most of Italy, North Africa, and a small foothold in southern Spain. Justinian's reconquests have been criticised by historians for overextending his realm and setting the stage for the Muslim conquests, but many of the difficulties faced by Justinian's successors were due not just to over-taxation to pay for his wars but to the essentially civilian nature of the empire, which made raising troops difficult.

paragraph_text: The Romans were the first known to use glass for windows, a technology likely first produced in Roman Egypt, in Alexandria ca. 100 AD. Paper windows were economical and widely used in ancient China, Korea and Japan. In England, glass became common in the windows of ordinary homes only in the early 17th century whereas windows made up of panes of flattened animal horn were used as early as the 14th century. In the 19th century American west, greased paper windows came to be used by itinerant groups. Modern - style floor - to - ceiling windows became possible only after the industrial plate glass making processes were fully perfected.

paragraph_text: As the Roman Empire was falling apart, Palermo fell under the control of several Germanic tribes. The first were the Vandals in 440 AD under the rule of their king Geiseric. The Vandals had occupied all the Roman provinces in North Africa by 455 establishing themselves as a significant force. They acquired Corsica, Sardinia and Sicily shortly afterwards. However, they soon lost these newly acquired possessions to the Ostrogoths. The Ostrogothic conquest under Theodoric the Great began in 488; Theodoric supported Roman culture and government unlike the Germanic Goths. The Gothic War took place between the Ostrogoths and the Eastern Roman Empire, also known as the Byzantine Empire. Sicily was the first part of Italy to be taken under control of General Belisarius who was commissioned by Eastern Emperor. Justinian I solidified his rule in the following years.

paragraph_text: Muslim rule started in parts of north India in the 13th century when the Delhi Sultanate was founded in 1206 CE by the Central Asian Turks. The Delhi Sultanate ruled the major part of northern India in the early 14th century, but declined in the late 14th century when several powerful Hindu states such as the Vijayanagara Empire, Gajapati Kingdom, Ahom Kingdom, as well as Rajput dynasties and states, such as Mewar dynasty, emerged. The 15th century saw the emergence of Sikhism. In the 16th century, Mughals came from Central Asia and gradually covered most of India. The Mughal Empire suffered a gradual decline in the early 18th century, which provided opportunities for the Maratha Empire, Sikh Empire and Mysore Kingdom to exercise control over large areas of the subcontinent.

paragraph_text: The Roman conquest of Britain was a gradual process, beginning effectively in AD 43 under Emperor Claudius, whose general Aulus Plautius served as first governor of Roman Britain (Latin: Britannia). Great Britain had already frequently been the target of invasions, planned and actual, by forces of the Roman Republic and Roman Empire. In common with other regions on the edge of the empire, Britain had enjoyed diplomatic and trading links with the Romans in the century since Julius Caesar's expeditions in 55 and 54 BC, and Roman economic and cultural influence was a significant part of the British late pre-Roman Iron Age, especially in the south.

Question: Who introduced a system of musical notation in the 14th century that is used in the area where most of the invasion of the eastern Roman Empire took place?
Answer: John Kukuzelis