When workers control their company, they want to ensure it performs as well as possible. To achieve the best possible outcomes, they need to make sure that workers—in the case of player-governed orchestras (PGOs), their musicians—perform as well as possible. The mutual monitoring of and by workers in labour-managed firms (LMFs) is thought to be a strength (Alchian & Demsetz, The American Economic Review 62 (5):777–795, 1972; Ben-Ner, Journal of Economic Behavior & Organization 10 (3):287–313, 1988; Bowles & Gintis, Economics and Philosophy 9 (1):75–100, 1993; Hansmann, The ownership of enterprise, 1996). Yet, talking with musicians showed that the mutual monitoring practised in PGOs is very difficult. Mutual monitoring will make or break a PGO, but the subjectivity of assessing musicians’ playing raises the stakes. Carefully considered processes and principles become necessary. This chapter explores quality assurance in PGOs from three angles: mutual monitoring, recruiting players, and managing generational change. Recruiting the best players is key to maintaining high performance. In a PGO, auditions cannot suffice, however. New members need to share the democratic and participatory ideas. Extra complexity colours the recruiting of players. The chapter’s final section considers generational change. As founders confront age-related declines in their playing difficult conversations need sensitivity so that players move on in the interests of the collective while the next generation maintains player-governance. This chapter deals with perhaps the hardest decisions facing player-governed orchestras.