This book looks at the only Welsh antiphonal known and discusses in particular the material for services celebrating the memory of the Welsh patron saint. The book has a full listing and description of the contents of the Penpont Antiphonal, National Library of Wales MS. 20541 E, and discusses the significance of the Office of St David. The chants and the literary text are described and discussed, supported by full transcriptions of the musical and literary texts, and by facsimile reproduction of the manuscript folios. The office is considered in its historical perspective, as evidence of the active cultivation of music in Wales during the Middle Ages, and for its relationship to other similar late medieval offices and to Rhigyfarch's Life of St David.