The theme of the essays in this volume is the identification of the resource which between c.1320 and 1642 the English Church saw fit to provide for the performance of the music of its liturgy. Individual essays describe the music and the choirs of Canterbury and Lincoln Cathedrals, Winchester Cathedral Priory and the private chapel of Cardinal Wolsey, while the personnel of the chapels of Edward III, the Black Prince and John of Gaunt emerge from study of the texts of compositions of the 14th century. From the alignment of contemporary musical and archival sources there arises a web of conclusions relating to the size of ensemble, vocal scoring and sounding pitch envisaged by its composers for English Church polyphony of the period c. 1320-1559. These essays thus encompass the two most profound of the revolutions to which the music of the English Church was subject at this period: the inauguration and widespread adoption of choral polyphony in the years c.1455-85 and the liturgical and doctrinal reformation of 1547 to 1563.