The purpose of this study was to examine agentic thinking among preservice music teachers through a “directed content analysis” (Hsieh & Shannon, 2005) of the written coursework of 2 cohorts of preservice music teachers (N = 66) enrolled in an introduction to music education course in order to advance knowledge of agentic thinking in music teacher education research and practice. We used a theoretical framework informed by Emirbayer and Mische’s (1998) triadic conception of agency that positions human agency at the nexus of 3 temporally oriented elements: iteration (past), projectivity (future), and practical evaluation (present). We investigated the agentic temporalities of different assignment types and analyzed the agentic vocabulary usage in premidterm and postmidterm assignments by cohort, identified gender, year in school, residency status, major, and applied instrument. We found slight differences in overall agentic vocabulary and vocabulary by agentic element between cohorts. Unexpectedly, we noted a marked decline in overall agentic vocabulary usage in postmidterm written assignments compared to premidterm written assignments. Analysis of change over time by agentic element found decreases in iterative and practical evaluative vocabulary and an increase in projective vocabulary usage in postmidterm written assignments. Findings from key-word-in-context analysis, however, suggest that a decline in agentic vocabulary may be related to a refinement in agentic vocabulary usage and an increased openness to different perspectives and career options. Based on our results, we argue that Emirbayer and Mische’s framework may provide music teacher educators and researchers with a nuanced tool by which to investigate, understand, and foster music teacher agency.