Music listening promotes adolescents well-being and relaxation in daily life. Relaxation is linked to affective self-regulation, but little is known about the specific affective processes of musical relaxation. The current study aimed to elaborate the affective dimension of adolescents musical relaxation, through detailed exploration of the related affect regulation goals, strategies, and induction mechanisms. A qualitative study with 55 adolescents (42 girls, 13 boys), aged 15, was conducted. Participants listened to self-selected relaxation music for 20min, once in a laboratory and once at home, and provided written descriptions of their experience. A total of 110 episode descriptions were analyzed using summative, directed, content analysis for identifying typical patterns and interactions between the underlying concepts. Three major strategies (processing, distraction, induction) and two mechanisms (musical and mental) were identified. Processing was supported by both mechanisms, while distraction and induction predominantly by the musical mechanism. Change from negative to positive mood was particularly realized through musical distraction, while pure positive emotion induction was equally supported by all strategies and mechanisms. The analysis revealed clear patterns of how affect regulation strategies and induction mechanisms interrelate and serve different outcomes as part of adolescents relaxation. The findings provide conceptual clarification and theoretical grounds for understanding how affective processes function in musical relaxation. The discussion is performed in light of prior research and broader understanding of music as part of adolescents affective processing and self-regulation.