David Simon and Eric Overmyer’s HBO series Treme took docudrama well past its previous boundaries, blurring the distinctions between the actual historical figures that populated the narrative and the fictional characters who were based on real New Orleanians.

Wendell Pierce, as the character Antoine Batiste, was at the vortex of this swiftly moving cultural identity tale. Batiste, a down-and-out trombonist trying to eke out a living on the fringe after the 2005 flood, grappled wit...