This paper aims at exploring diverse stages in the research on the educator, passing through three specific moments: in the first one, the research focuses on the teacher's skills; in the second, on the education philosophy, and finally, the knowledge of the educator is analyzed in the third one.The professional knowledge of teaching diverges from the exercise of a specific discipline; thus, for example, to be a teacher of music is not the same thing as being a musician.From this perspective, two different research approaches on the professional knowledge of the teacher are herein presented: the first one is that of the Research and School Renewal Group (IRES) from the University of Seville, while the other comes from the research group Through the Classrooms of Colombia (INVAUCOL), from the Universidad Pedagógica Nacional of Colombia.After analyzing the panorama about the teacher's professional knowledge, the article closes by asking some questions and advancing some proposals on the formation of music educators.