This book makes an important contribution to the expanding body of work in generative phonology which aims to reduce the number of traditionally recognized melodic categories in order to achieve a greater degree of restrictiveness. By analyzing data from a large number of different languages, Nasukawa establishes a clear affinity between nasality and voicing, and demonstrates the advantages of treating these two properties as different phonetic manifestations of a single nasal-voice category. The choice of whether to interpret this category as voicing or nasality is determined by the active or inactive status of a complement tier. This study deepens our understanding of the typological relation between nasality and voicing, and sheds new light on a number of related agreement phenomena.