Despite the importance institutional theory places on the temporality and timing of organizational behavior, the literature on institutional entrepreneurship has asked how rather than when embedded organizations engage in institutional reform. To examine when embedded organizations expedite or delay involvement in institutional entrepreneurship, we design a unique case study in the field of music promotion in the United States that has undergone significant institutional reformation characterized by integration, digitalization, and globalization since the early 2000s. Drawing from historical institutionalism, we build propositions to argue that embedded organizations are more likely to engage in institutional entrepreneurship during critical conjunctures – multiple unfolding event sequences in the institutional field interacting to unpredictably interrupt the mechanisms of institutional reproduction (sources of status, legitimacy, and identity) within an organizational field. We argue that embedded organizations that are mindful of shifting identities, material practices, and sources of status and legitimacy, and that (serendipitously) hold a consolidating advantage – prior strategic orientation, related capabilities, and social capital relative to critical conjuncture – are more likely to engage in institutional entrepreneurship. Our resulting propositions have several implications for the theory of institutional entrepreneurship in mature fields.