Neither Michael (Imana Breaux) nor Sean David (Adrain Washington) would recognize their present-day San Francisco hometown.  The aspiring artists' relationship, told in Ntozake Shange's  a photograph/lovers in motion, develops during the late 1970s-early 1980s before SF's gentrification for the super rich and high tech.  While SF is not a "character",characters define themselves by it.  A rare revival of Shange's 1977 play is presented by The Negro Ensemble Company, Inc.'s  plays through the end February at  Theatre St. Marks. Directed by Shange's sister and long-time collaborator Ifa Bayeza, a photograph/lovers in motion has the same lyricism found in her landmark for colored girls who have considered suicide/when the rainbow is enuf