One of the most long-lived and most important of all sacred musical traditions is the use of plainchant as the basis of composed polyphony: the very earliest surviving examples of polyphony are of this kind, and the practice continues up to the present day. Nonetheless, the persistence and centrality of this practice, at least during the 16th century, is typically historiographically marginalised. An assessment of the relationship between chant traditions and the music of Orlando di Lasso offers an especially rich opportunity to re-address the issue from a variety of perspectives.

Lasso’s music in particular is taken to embody a new, personal, and dramatic style, making it easy to overlook the extent to which a significant part of his prolific output is rooted in tradition. This paper will present an overview of the place of chant-based composition within his oeuvre that attempts to redress this. Furthermore, the composer’s cosmopolitanism brought him into contact with a wide range of chant traditions, he lived through the drastic liturgical revisions of the Council of Trent, and, in Munich especially, he was heir to particularly vibrant and well-established tradition of chant-based music, based in the works of Heinrich Isaac and Ludwig Senfl. The paper will analyse and compare selected chant-based works from different points and places in Lassus’s career in order to shed light on the ways in which these experiences are reflected in his works.