Pacherie (2012), The phenomenology of joint action · Bishop (2018)
Two modes. Pacherie distinguishes “we-agency, where self-boundaries and sense of self-agency appear to dissolve into the collective, and shared agency, where self-agency and joint-agency are articulated rather than fused” (2012). Taking self-agency as a baseline gives three steps rather than two.
Hard to measure. Reviewing collaborative musical creativity, Bishop notes that emergence “requires comparing the combined output of an ensemble to the output that individuals would produce if performing their part alone” (2018), and that systematic empirical studies testing such models are largely absent.
Used here as the collective half of the agency question, alongside musical agency.