According to International and European Law, teachers are encouraged to analyse, challenge and to help to eliminate sexist stereotypes and distortions in curricular materials. We aimed to characterize and compare the efficacy of implementation of the gender equality-based approach in the Spanish educational system, through a content analysis of the illustrations in music education (ME) textbooks following a coding scheme constructed by the research team according to guidelines from previous studies about the depiction of women and girls in ME textbooks during two periods of Spanish democracy: before (1992–2005); and after (2006–2015). Our major findings were: (a) female characters were under-represented in both time periods studied; (b); the stereotype of women as amateur but not professional musicians is not perpetuated in the current primary ME textbooks; (c) both children and adults independently of gender were portrayed interacting with others; (d) despite the fact that women teachers are actively participating in schools, ME textbooks do not faithfully reflect that reality; and (e) the virtual absence of females and males with disabilities suggests that this aspect of inclusion is still pending. Notwithstanding, ME textbooks printed after 2006 tended to challenge some traditional stereotypes pertaining to how females and males think, play and act within the musical world.