After sharing research findings about grading and assessment practices in secondary music ensemble classes, we offer examples of commonly used assessment tools (ratings scale, checklist, rubric) for the performance ensemble. Then, we explore the various purposes of assessment in performance-based music courses: (1) to meet state, national, and school mandates; (2) to provide documentation for grades; (3) to improve individual musicianship and understanding; and (4) to improve instruction. Finally, we conclude with assessment dilemmas and questions for consideration.