There is now an accepted need for initiatives that support older people's well-being. There is increasing evidence that active engagement with music has the potential to contribute to this. This paper explores the relationship between musical possible selves and subjective well-being in later life. The research reported here formed part of a larger project that focused on how active music-making could support positive cognitive, social and emotional outcomes. The research comprised three UK case study sites, each offering diverse musical activities. A sample aged 50+ (total "N" = 398), some of whom were novices and others who are more experienced, was recruited to complete questionnaires that included open questions and measures of well-being. In addition, individual interviews ("n" = 29) and focus groups ("n" = 15) were carried out, where participants in musical activities reflected on the meaning and function of music-making in their lives. The interpretation presented here suggests that through music many older people found a means by which they were able to formulate well-understood and highly esteemed versions of their possible future selves. This, in turn, may have been a significant factor in helping to navigate the process of ageing in later life with enhanced subjective well-being, including a sense of purpose, a significant degree of autonomy and a strong sense of social affirmation.