In conjunction with the new documentary film “The Black Power Mixtape 1967-1975” (reviewed by our own Bill Morris last week), New York’s Third Streaming Gallery will be hosting a conversation on the role of art and artists in contemporary cultural activism. The discussion will be held tonight at 7pm, and it will include Rico Gaston, Jacqueline Hoang Nguyen, Donna Murch, and Minkah Makalani.