Mattias Lundberg investigates the historical role of a deviant psalm-tone, the tonus peregrinus, focusing on its applications in polyphonic music within all major branches of Western liturgy. Throughout the remarkably persistent tradition of applying this melody to polyphony, from the ninth century right up to the twenty-first, coeval music theory is able to shed light on the problems it has posed to modal and tonal practice at various historical stages.

Contents: Preface; Theory, method and conventions; Historical background of the tonus peregrinus in monophonic practice; Singled out as a model: the tonus peregrinus in polyphony before 1500; The role of the tonus peregrinus in the extended modal systems of Glareanus and Zarlino; The rise of an idiom: the tonus peregrinus in French court liturgies of the 16th century; Ambitious obbligo or lack of invention: the tonus peregrinus in Italian-speaking areas during the 16th century; Liberty with rigour: the tonus peregrinus in 16th-century Iberian music; Total thematicism and multi-texted motets: the tonus peregrinus in 16th-century Roman Catholic liturgies of Northern and Central Europe; Mit Szonderlicher Ziemlicher Weisz: the tonus peregrinus in 16th-century Lutheranism; In Faburden and upon Faburden: the tonus peregrinus in 16th-century English liturgies; One applied and one discreet method: the tonus peregrinus in Roman Catholicism 1600-1750; A hand-maiden of many different voices: the tonus peregrinus in Lutheranism 1600-1750; The continuing tradition: the tonus peregrinus in music after 1750; Conclusions; Bibliography; General index.