Zooming in on a single city, Chapter 4 focuses on Paris in the twelfth and thirteenth centuries. As a prime example of the social changes brought about by urbanization, Paris was a commercial hub, the seat of royal administration, and a centre for advanced learning and education through its new university. We explore how this environment fed into the cultivation of polyphonic music at the Cathedral of Notre-Dame, looking into the genres of organum, conductus, and motet, and examining the system of rhythmic modes that was developed to notate this music for posterity. Music theorists, writing a generation or more later, provide us with the names of some of those musicians responsible for the musical innovations at Notre-Dame, and thus we can identify the composers of liturgical polyphony for the first time. We learn how Léonin compiled his Magnus Liber Organi, and his successor Pérotin edited and supplemented it, giving us a unique insight into the ways in which medieval musicians preserved and reinvented the music of earlier generations.

Chapter 2 explores the music produced in the monastic institutions of ninth- to eleventh-century Europe. Describing the context of the Carolingian Empire, and the renaissance of learning, literacy, and writing that it brought about, we look at some of the earliest examples of musical notation from this vast region of Europe. We examine the Latin songs, or versus, produced in monasteries, charting their wide range of themes and their possible functions in monastic life. Our earliest evidence of polyphonic singing in church comes from music theory texts dating from the ninth century onwards: we consider what these texts can tell us about the improvised practice of organum (or parallel organum) singing, and provide a practical exercise for readers to try improvising organum themselves. Further music theory texts from the tenth and eleventh centuries document the changing approaches to organum singing over the period, and finally we consider how music theory related to actual practice, by looking at the first surviving examples of practical polyphony from medieval Europe.