This study explores the four Passion settings of Orlando di Lasso, composed between 1575 and 1582, which have largely been ignored by music scholars. Scholars have recognized that a dramatic compositional shift occurred between the second and third settings, but have provided no cogent explanation for the change. Most reasons given revolve around the Council of Trent, which held its final session in 1563. However, a consideration of the history and religious contexts of the works discloses other, possibly better explanations. I propose that the primary influence leading to Lasso's compositional shift was the liturgical reform initiated by his employer, Duke Wilhelm V, and enforced by the Jesuit priest Walram Tumler. These reforms had a profound effect on all facets of worship in Bavaria, most notably music. Recognizing the influence of the Jesuits on Lasso's music makes it possible to understand the composer's dramatic change in style.