This paper reports on the evaluation of the In2 music project in Darlington, England. The project ran for seven weeks from January-March 2020 and involved Year 6 pupils from four primary schools (n = 103) and Year 7 pupils from one secondary school (n = 90), working with Back Chat Brass, a professional brass ensemble. The aim of the In2 music project was to enable pupils to work with professional musicians to enjoy the benefits of group-based music, which include happiness and optimism. These emotions are strongly associated with social capital, which this study defines as the benefits that individuals and communities derive from positive interpersonal relationships. This evaluation asks if the In2 music project resulted in non-quantifiable changes that are associated with positive outcomes for pupil wellbeing and social capital. We explore our findings in relation to a policy climate of cuts to arts education, as shown by the stories in a special issue of Arts Education Policy Review. We argue that while political disregard threatens the development of social capital in economically deprived communities, funded interventions such as In2 can benefit some of the most vulnerable members of such communities.