This paper presents an exploration of the ontological shift from musical materials (i.e. melody, harmony, rhythm, texture, timbre, register) to activities in music performance analysis. The “dogmas” extend Herbert H. Clark’s conceptual framework for the study of joint activity in language use to explore music performance in the WAM tradition. A systematic analysis of London Symphony Orchestra masterclasses examines the basic mechanisms of music making in four main areas: representation, audience, interaction, and tacit knowledge. This exploration leads to a broader account of cognition and creativity in music performance, one that bridges inner and outer processes of awareness around domains of coordination in joint activities. In this view, material conceptualizations are viewed as targets of focal awareness rather than the basis for cognition in music making. This account, grounded in a rich third-person phenomenological analysis of instructional materials, paves the way for a “meaningful analytics” of musical practice.