Musical scores are some of the most important learning tools for musicians' acquisition of musical knowledge. However, despite their educational relevance, very little is known about how music students "conceive" of these cultural external representations. Given that these conceptions might act as mediators of students' learning approaches, the importance of knowing these conceptions seems evident in order to eventually change them. The general aim of this investigation was to study the conceptions of piano students at Spanish music conservatories by adopting a developmental-instructional perspective. The participants were 215 students at intermediate and tertiary degree levels, representing three levels of the collapsed variable age-level of instruction. Data were collected by means of a written open-ended task and analyzed by means of descriptive, parametric, and nonparametric statistical methods. The findings suggested that (a) students' conceptions were more sophisticated at higher age and education levels, (b) each developmental-instructional group typically focused on different musical aspects, which reflected an inclusive and hierarchical logic, and (c) five increasingly sophisticated conceptions could be identified among these students. (Contains 8 tables, 1 figure and 3 notes.)