This paper draws on three different research projects to demonstrate the use of an expanded model of Cultural Historical Activity Theory (CHAT), developed as part of a doctoral research study. The first project is an evaluation of the impacts of a Music Partnership Project within Primary and Secondary schools. The second project is an evaluation of the Good Vibrations Javanese Gamelan project in male and female prisons. The third project is an exploration of the learning processes within a Good Vibrations Javanese Gamelan Project in a young offenders' institution. CHAT provides a lens for analysing activity, placing the interactions between the individual, individual cognition and the socio-cultural environment at the heart of the analytical framework. Although a useful way of looking at activity in order to understand the individual and social processes occurring in a learning activity, criticisms of CHAT include the rigidity of the unit of analysis, its inability to view progression and transformation and the focus on one individual without taking into account the labour power that a group offers.