BackgroundInstrumental practising[1] is considered a primary activity for developing skills on an instrument. However, characteristics of practising - such as amount of time used and how knowledge on practising is articulated - may vary depending on musical genre, learning context, instrument group, and individual experience. The present study aims to investigate the teaching of practising among instrumental teachers at the music program at upper secondary schools (USS)[2]. Research on instrumental learning at the USS is scarce.Research perspectives on practising have traditionally entailed individual features such as motivation, planning and execution strategies as well as self-regulation. Practising has also been regarded as situated in sociocultural systems. In the present study we employ the notion of practising as a knowledge culture (Knorr Cetina, 1999, 2007; Knorr Cetina & Reichman, 2015), which highlights a shared repertoire of knowledge resources (Lahn & Jensen, 2008), such as routines for collaboration and domain-specific conceptual systems and value judgements.Commonly, practising studies have investigated learning in western classical music centering on privatised settings and learning from scores, sometimes tacitly assuming transfer to other musical genres. Employing the framework of knowledge cultures allows for addressing differences in cultural values and the production of knowledge resources across genres.Research questionsWe ask:What do teachers consider valid knowledge about practising, and how do they establish relevance for their views?Which factors do teachers perceive as contributing to productive learning dynamics?MethodThrough a qualitative approach, we embrace variation and in-depth understandings. Seven instrumental teachers from three different USSs were interviewed. Schools were selected based on variation in genre profile as well as location and demography. The interviewees differed regarding educational background, genre, teaching experience, main instrument and gender.Preliminary results and conclusionA preliminary analysis indicates that all teachers, regardless of genre, are deeply engaged in developing productive practising cultures among students. However, articulations of valid knowledge are highly genre-specific, as are value judgements and cultures for collaboration. Our findings lead to a discussion of how sharing of knowledge and values across genres may increase access to knowledge resources that can contribute to a richer learning repertoire and more dynamic practising cultures among instrumental students.[1] Our use of this term includes vocal practising.[2] Nationality removed due to anonymization.