Upper- or upper-middle-class whites volunteer to be submitted to abuse by black people, like performance art whose value is in the experience.  It’s like a show they bought tickets for, but that they also participate in.  Filmed in black and white, probably in the 60s, maybe early 70s.  The whites are conciliatory and the blacks are verbally (maybe physically?) abusive.  It’s set in Manhattan, I think, in a warehouse that the whites allow themselves to be confined in.  Filmed as if a documentary, as if it were really happening.