Thomas Morley's Plaine and Easie Introduction to Music is one of the most famous publications in the history of European music theory. Morley's treatise is familiar to musicologists, students of early modern England and devotees of early music. Yet substantive scholarship on many aspects of the treatise is surprisingly lacking. This may be due in part to the absence of a critical edition. In setting out to create a new critical edition, Jessie Ann Owens and John Milsom drew on the expertise of a collection of distinguished scholars of early music, in a series of meetings that came to be known to its participants as 'The Morley Project'. This volume is a collection of essays by the participants in the Morley Project, each of whom takes as topic one of the issues that have been considered in the making of the critical edition. Among the topics, whose coverage has implications that reach far beyond this one treatise, are Elizabethan print culture, dialogue form in early modern scholarship, Morley's theoretical background and influences, English and continental theory, and the role of music theory in the formation of canon.