This research aims to understand the impact, unfolding and repercussions of music education in the prison context, and how these musical practices alter the intrinsic and peripheral relationships of the prison system, through the comparative analysis of three case studies, fruit of research and music education projects in this specific environment. Firstly, an explanation was given of the concepts that permeate music education and social projects in Brazil, based on Kleber (2014) and Souza (2014). Subsequently, projects related to music in prisons in various Brazilian states were presented in accordance with the Ministry of Justice's national document 'Good Practices in the National Penitentiary System'. The methodology used for this study was bibliographical research that uncovered two studies and a music education project in three prisons: Presídio Regional de Santa Maria (PRSM), Rio Grande do Sul; Penitenciária Dr Francisco Nogueira Fernandes (Alcaçuz), Rio Grande do Norte; and Penitenciária Industrial de Cascavel (PIC) in Paraná.