ABSTRACT Based on 2 years of ethnographic fieldwork with builders of boutique music effects boxes, this essay explores the ways in which improvisation figures into the creation of music technology. The author argues that expanding the rubric of improvisation to encompass the processes of designing and building effects boxes pushes scholars to understand relationships between music and improvisation as existing beyond the boundaries of performance. Ultimately he posits that improvisatory behavior and exploratory engagement with material at hand is central to building pedals, and should be assessed as part of the continuum of social-aesthetic practices composing music making.