Half a century ago, calls had already been made for instrumental ensemble directors to move beyond performance to include the teaching of musical concepts in the rehearsal hall. Relatively recent research, however, suggests that conceptual teaching remains relatively infrequent during rehearsals. Given the importance of teaching for long-term musical goals, revisiting this critical topic, backed by research and learning theories, is important and timely. Enriched by insights from my own teaching experience, the goal of this article is to clarify the nature of conceptual teaching and encourage conceptual teaching in large instrumental ensembles by addressing the following questions: What is conceptual teaching? Why teach conceptually? and How may musical concepts be taught through the rehearsal hall? I conclude with some thoughts on the future.