Listening is central to all musical activities, and semiotic means for visualizing, representing, and conceptualizing music are central to educational endeavors aimed at developing trained listening (Bamberger, 2013; Wallerstedt, 2011; Wallerstedt, Pramling, & Säljö, 2014). There is, however, a lack of research on how such semiotic means are taught and learned, especially in secondary education. The aural skills and music theory subject at this educational level is an educational context that has received relatively little research attention and provides a promising arena for studying the teaching and learning of music-theoretical concepts and models. This paper reports on research aiming to address these issues by investigating upper secondary music students’ processes of learning the circle of fifths and some associated music-theoretical concepts, and how those processes relate to the practice of aural skills and music theory education they are engaged in. I ask two research questions: 1.How do participants introduce, reproduce, and use the circle of fifths in the educational practice? 2.How do the specific ways in which the circle of fifths is introduced, reproduced, and used in the educational practice facilitate learning processes? Theoretically, the study draws on Vygotsky’s (2012) distinction between scientific and everyday concepts, and conceives of the circle of fifths as an inscription (Latour, 1987; Roth & McGinn, 1998). The study takes a qualitative case study approach, combining interviews with students and observation of lessons, both documented by video. The analysis focuses on how participants interact, how they use inscriptions, and on how this constitutes co-constructive microgenetic processes (Valsiner, 1996; Wagoner, 2009). The analysis shows an educational practice where the circle of fifths is deployed as a tool for solving transposing problems, and where the ability to use mnemonic techniques to reproduce the diagram is highly valued. This focus on mnemonics and algorithms for problem-solving tends to foreground the logic of the representation, rather than the logic being represented. This appears to make it difficult for students to apply the algorithms on different related problems. For example, circumscribing a group of chords in the diagram is used to represent a key. This makes it difficult to distinguish major and minor keys, and to conceive of key as a property of melodies. The varied level of previous knowledge among the students means that the teacher needs to build a common set of concepts from a disparate set of antecedents. It is proposed that this challenge, together with a lack of musical examples and formal definitions leads problems with circularity: The circle of fifths is used to visualize central concepts, which are then used to explicate the circle of fifths, creating a circular conceptual system. I discuss these results in relation to a prevalent discourse downplaying the importance of symbolic and conceptual knowledge in music education (e.g. Gruhn, 2006; Stewart Rose & Countryman, 2013). References Bamberger, J. (2013). Restructuring conceptual intuitions through invented notations: From path making to map making. In J. Bamberger (Ed.), Discovering the musical mind: A view of creativity as learning (pp. 49–80). Oxford: Oxford University Press. Gruhn, W. (2006). Music learning in schools: Perspectives of a new foundation for music teaching and learning. Action, Criticism & Theory for Music Education, 5(2). Latour, B. (1987). 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