This article considers some paradigms of educational research, and their relation to teachers' action research in their classrooms or studios. The positivist/scientific paradigm and the interpretive/naturalist paradigm are examined, with reference to two cases of music teachers' action research studies. These studies are found to be flawed because the paradigms underpinning them are inappropriate for classroom-based action research. The critical theory approach is also discussed but only briefly, because no instances of music teachers' action research in this paradigm have been found. The participatory paradigm is explained, with reference to a third case of music teachers' action research. The article argues that, for teachers' classroom-based action research, this paradigm is more appropriate than others. It suggests that music teachers' action research in the participatory paradigm: (a) includes self-study, (b) involves students, (c) considers the influence of context, (d) involves more than one turn of the action research cycle, and (e) engages with, and contributes to, the development of theory.