With the articulation of new "Holistic and Balanced Assessment" initiatives in Singaporean schools, a new standard of conceptualising and enacting classroom assessment is expected of Singaporean teachers. This paper draws on findings from a study of the diversity of classroom assessment "concourse", representing the variations in conceptions among the case studies of Singaporean primary- and secondary-school Music teachers, higher-education Music teachers and policy-makers. As such, the emphasis is on unravelling the multiplicity of significant relationships of conceptions within the specific context of Music teachers' classroom decision-making environments. The different conceptions from the Q-factor analysis, in particular, have revealed underlying bases of common and different views of classroom assessment. This suggests that classroom assessment, like many aspects of classroom teaching and learning, is not a stable entity. Rather, it is highly variable, contested and irreducibly situated in a specific context. The imagination, conviction and commitment of Music teachers, can inspire the wider education fraternities to consider how assessment can be compatible and complementary to the creativities of learning and teaching in the classroom.