It is the variation in plainsong, its living quality, that these essays address.From at least the eighth century and for about a thousand years the repertory of music known as Georgian chant, or plainsong, formed the largest body of written music. But plainsong did not follow rigid conventions. It is just this variation, this living quality of plainsong, that these essays address.From at least the eighth century and for about a thousand years the repertory of music known as Georgian chant, or plainsong, formed the largest body of written music. But plainsong did not follow rigid conventions. It is just this variation, this living quality of plainsong, that these essays address.From at least the eighth century and for about a thousand years the repertory of music known as Georgian chant, or plainsong, formed the largest body of written music AND was the most frequently performed and the most assiduously studied in Western civilisation. But plainsong did not follow rigid conventions. It seems increasingly clear that, whatever may have been intended with respect to uniformity and tradition, the practice of plainsong varied considerably within time and place. It is just this variation, this living quality of plainsong, that these essays address. The contributors have sought information from a wide variety of areas: liturgy, architecture, art history, secular and ecclesiastical history and hagiography, as a step towards reassembling the tesserae of cultural history into the rich mosaic from which they came.Introduction Thomas Forrest Kelly; 1. Plainsong and polyphony 2501550 John Caldwell; 2. Notated performance practices in Parisian chant manuscripts of the thirteenth century Michel Huglo; 3. The geography of the liturgy at Notre-Dame of Paris Rebecca A. Baltzer; 4. The Feast of Fools and Danielis Iudus: popular tradition in a medieval cathedral play Margot Fassler; 5. The Mass of Guillaume de Machaut in the cathedral of Reims Anne Walters Robertson; 6. Sacred polyphonlóC