Recommendations for the assessment of music at Key Stage 3 now accompany the revised National Curriculum for both England and Wales. Although some of the material may be helpful to teachers, certain underlying assumptions compromise valid and reliable assessment. Weaknesses arise from initial confusion when formulating attainment targets, the vagueness and ambiguity of music curriculum wording and reliance on End of Key Stage Descriptions for assessing the work of pupils throughout the whole key stage, causing elements of complexity and range to be inappropriately introduced at each assessment point. This article offers an alternative model that puts the assessment of musical quality first and defers the assessment of musical complexity and range of styles until there are pupil profiles later in the key stage.