The introduction of the General Certificate of Secondary Education (GCSE) in 1986 marked a significant shift in music education practice across England, Wales, and Northern Ireland. Unlike previous qualifications, the GCSE emphasised a central triumvirate of accessible, practical skills – performing, composing, and appraising – which, forty years later, remain foundational in secondary music education across the three nations. In this article, we therefore analyse how the tripartite performing–composing–appraising structure has shaped the development of the GCSE between 1986 and 2026. Using historical and documentary evidence, we identify four trends of political quiescence, progressive divergence, neoliberal convergence, and neoconservative coalescence, and suggest that across all three nations a subtle shift towards a fourfold performing–composing–knowing–appraising framework is beginning to erode the GCSE as an accessible, practical approach to assessment.