The purpose of this study is to investigate how children (aged 6 to 8 years) appropriate concepts relevant to making distinctions about music. In particular, the focus is on how they perceive and describe differences in time in pieces of music. The data were generated through interviews with children. The results show that there seems to be a developmental trajectory from a point where children are unable to discern differences in time in music, via a situation where they perceive such differences but account for them in an ad hoc manner, to a stage where they are able to discern and explain such differences in institutionally relevant concepts. In addition, the study documents how children – operating in the zone of proximal development – may be scaffolded in interaction with a more competent person to appropriate such institutionally relevant distinctions. It is argued that this developmental trajectory describes the development of a cultural skill where children increase their ability to structure music through bodily performance and in linguistic terms. Through this development they also become more skilled at communicating about significant features of music. Generally, in research analysing learning these processes of appropriation and scaffolding are presumed rather than made explicit.