In the author’s practice-led research into timbre transformation and the devices required to construct a coherent musical form with a very slow distribution of structural sound events, the aesthetic of the music conflicts with the physical limitations of human ensemble performance. This chapter traces the development back to the 1950s and the ‘mobile score’ experiments of Earle Brown, John Cage and Morton Feldman. The music can be described as slow and stretched out, quiet and fragile, tense and sustained; it is moderately dissonant, with non-directional harmony projected as cyclical transformations of two starting-point chords. The composition has a slow perceived tempo of unfolding. This is achieved by means of a careful placement of stronger musical gestures at timed intervals averaging eight seconds, but ranging from 0.5 seconds to 24 seconds. In order to maintain musical interest over the course of the composition, the decision was made to explore varying textural relationships between the main instruments.