The music of Jakob Ullmann (b. 1958) is notable for its protracted structural stasis and delicacy; its fusion of rigorously engineered notational systems, abstract graphical elements and Byzantine iconography; and – above all – its unrelenting quietness. This article offers a rare view into Ullmann's compositional practices, with a specific focus upon the role of fragility in the work. Exploring this concept of fragility as a musical feature, this article considers a number of Ullmann's works from the perspectives of the compositions and their scores, the performance and the agency of performers and, finally, how audiences may listen to this fragility. The article concludes with a consideration of the importance of fragility to Ullmann's oeuvre, and of how it might help us to further understand his music.