Contents: Introduction; Part I The Sources and Practice of Medieval Cerdd Dant: Cerdd Dant: a Welsh bardic craft in context; Mastering the bardic crafts: oral and written sources; Harp and crwth in early medieval Wales; The players of Cerdd Dant and their social code; Gathering the documentation of Cerdd Dant; Historical and theoretical sources of Cerdd Dant; The Robert ap Huw manuscript and other Welsh tablature. Part II The Latin Liturgy, its Chant and Embellishment: Sources for the medieval Welsh liturgy: an overview; The early Welsh Clas institutions; Anglo-Norman liturgical reform; Shaping a new liturgy: the adoption of Sarum Use in Wales; Sources with music I: the Penpont Antiphoner; Sources with music II: the Bangor Pontifical; Late medieval evidence I: the institutions; Late medieval evidence II: musical practice. Part III Welsh Music in an English Milieu c.1550–1650: Mirroring England: cultural imitation and infiltration; Domestic and popular music-making I: the context; Domestic and popular music-making II: the repertory; A Welsh translation of John Case's Apologia Musices; The post-Reformation church I: parish and people; The post-Reformation church II: cathedral and household chapel. Appendix of manuscripts; Bibliography; Index.