While research on teaching praxis is abundant, few studies have focused on analyzing instances of malpractice, that is, classroom practices that are incongruent with principles commonly accepted within curriculum, pedagogical and/or didactic frameworks. The theoretical framework of educational malpractice proposed by Herrán and González, which deals with the influence of egocentricity, holds great potential to better understand issues that have been traditionally observed in instrumental teaching within conservatories and music schools, both in Spain and other countries. The present qualitative and critical bibliographic analysis has two objectives: (1) to introduce the above-mentioned theoretical framework to instrumental teaching professionals, by illustrating its key tenets referring to prior research in the area; and (2) to propose strategies to prevent malpractice within conservatories and music schools, drawing on the teacher professional development literature. The strategies proposed involve nurturing teachers' identity as music educators via stronger pedagogical training, enhancing recruitment and induction procedures, and fostering professional development and collaborative work. We conclude by arguing that preventing malpractice in conservatories and music schools requires to rethink the ultimate goal of instrumental teaching and learning in our current society. [ABSTRACT FROM AUTHOR]