
Bewerung's article in the Catholic Encyclopedia. Traditionalists point to evidence supporting an important role for Pope Gregory the Great between 590 and 604, such as that presented in H. Scholars debate whether the essentials of the melodies originated in Rome, before the 7th century, or in Francia, in the 8th and early 9th centuries. Other scholars, including Andreas Pfisterer and Peter Jeffery, have argued for an earlier origin for the oldest layers of the repertory. According to James McKinnon, the core liturgy of the Roman Mass was compiled over a brief period in the late 7th century. The Gregorian repertory was systematized for use in the Roman Rite. By these paths Gregorian chant came to dominate liturgical music in the West by the 8th Century. Others were abandoned when the region resolved to adopt what it considered a superior chant or liturgy. Some of these chants were suppressed by Roman pontiffs striving to establish a unified liturgy and music for the Church. From Milan came Ambrosian chant, named in honour of St Ambrose from Gaul, or what is now France, Gallican chant from Rome, Old Roman and Gregorian from England, the Sarum from the Church in the East, Syrian, Byzantine, Coptic, Ethiopian and Armenian. In fact, the chant was composed and complete by the 7th Century, and altered little thereafter. Roman Spain produced Mozarabic chant, whose title refers to the Moorish rule over Spanish Christians after the invasion of 711. Following the legalisation of Christianity in 313, different forms and flavours of chant began to develop by region. Unaccompanied singing has been part of the Christian liturgy since the earliest days of the Church. This single line of melody, called monophony, characterized music until about 1000 AD. Manuscripts date from ninth century and used a system of modes, specific patterns of whole and half steps.

This music consisted of a single line of melody with a flexible rhythm sung to Latin words by unaccompanied male voices.

The sacred music of the Gregorian Chant was also known as plainchant, or plainsong and named after Pope Gregory. Origins are traditionally are ascribed to the period of Pope Gregory I 590-604. Gregoran chants are a body of chants of the Roman Catholic Church, most of which are part of two liturgical rites, the Mass and the Offices.
