This book is a collection of articles examining liturgical music from classical Greece and ancient Israel to late 15th-century Flanders and Spain. The focus is on two main topics: the negative role of instruments in ancient cult music; and the development of ecclesiastical song in early Christianity. Presented in this book are 16 articles written by the author over a period of 30 years. They span two millenia in their coverage, ranging from classical Greece and ancient Israel to the late 15th-century Flanders and Spain. Liturgical music in some form or another is the theme that binds them together, and two topics in particular are focused on: the negative role that instruments play in ancient cult music; and the development of ecclesiastical song in early Christianity. For the negative role of instruments, a series of articles treats classical Greek ethical notions of instruments, the status of instruments in temple and synagogue and the absence of instruments from early Christian and medieval Church music. The second focus - that of the development of ecclesiastical song - is dealt with in several studies that trace the psalmody and hymnody of the Christian tradition from its roots in Judaism to the origins of Gregorian chant in 7th-century Rome. The articles rely strongly on the writings of the Christian Church Fathers, such as Augustine, Basil and John Crystostom.