Based on Bandlien’s micro-ethnographic study, where eighth-grade pupils composed music on an iPad, this chapter questions how pupils who are composing on an iPad are challenged to engage and to reflect in their encounter with that kind of technology. In line with a design-theoretical perspective, technology is regarded as an orchestration of semiotic resources in a social context. By applying a performative inquiry, focusing on stop moments in the pupils’ processes, we argue that iPad composing can be a teaching practice where pupils’ own active performative contributions become the core of the learning activity.