Teachers and mentors in creative fields shape their students’ skills and views of the craft and thus the work they produce. How significant and persistent is this influence? Are there consequences for the variety and quality of students’ inventive output? We study these questions in the context of Western music composition over five centuries, during which musical lineages are well documented, the content of composers’ work can be directly compared, and its lasting value can be measured. We find strong evidence of influence, document when it arises and persists, and evaluate its consequences. The results provide insight into where creative ideas come from, why certain ideas get produced as opposed to others, and what the ramifications might be.