This presentation written and given by Barbara Haggh-Huglo on October 20, 2014, as part of the Autumn School held in Ghent, Belgium, provides an introduction, in Part I, to the chanted texts for the Mass and the Sacraments of Western Christianity in the Middle Ages, and in Part II, to the chanted texts for the Office and Votive Services. An extensive bibliography is included at the end of the PDF.