Evidence points towards the key role that networks of both formal and informal relationships play in musicians’ careers. Alongside this, these careers have in recent decades become increasingly understood as engendering emotional stressors around mental health and wellbeing. However, what is the relationship between these two phenomena? In other words, what is the affective impact on musicians’ mental health of maintaining, understanding and negotiating the most proximate relationships in their lives? This paper seeks to answer this by employing the conceptual architecture of relational work, focusing in particular on the experiences of ‘mismatches’, to interpret insights from semi-structured interviews with twenty-eight musicians working in the United Kingdom. The findings suggest that that the relational work of ‘matching’ relationships to appropriate understandings and methods of transactional exchange is enormously complex for musicians given that that their economic relationships often are intimate personal relationships, and vice versa, leading to frequent ‘mismatches’ in musicians’ methods of relationship management which can be upsetting or emotionally destabilising. This is revealed by exploring the overlapping and interconnected forms of relational work employed by musicians amongst both their family and their musical colleagues. The findings contribute towards scholars adopting an affective frame of analysis towards practices of relational work, an emerging body of work primarily from Eastern Europe applying relational work analysis towards musicians, and more broadly researchers interested in understanding the psychosocial causes of mental ill-health amongst musicians.