This collection of essays celebrates the work of the Plainsong and Mediaeval Music society and was written in particular to celebrate their centenary. Founded in 1888, the Society quickly established two areas of activity: to propagate information on medieval music and to revitalize theAnglican liturgy with the riches of the plainchant of the Roman Rite.Of the two sides of the Society's activities, the scholarly and the practical, this collection represents the former. The essays reflect the founders' interest in medieval music, both monophonic and polyphonic, and, particularly, their concern with chant. From its inception, the PMMS has directedmuch of its attention to the British source of medieval music, the music which might contribute to a renewal of the liturgy of the Anglican church, and this is reflected here. The contributors to this volume are among the most distinguished scholars of medieval music of recent years. Their essaysare complemented by many music examples and a number of line drawings.