This is an award-winning adaptation of what some consider to be America’s main contribution to the operatic tradition, Porgy and Bess. The story behind it is this: The famous white director Diane Paulus made considerable changes to the 1935 libretto by the Gershwin brotherswith assistance from the famous black American playwright Suzan-Lori Parks. It seems Paulus and Parks drew these changes right out of reality and also right from the source for the opera itself, the novel Porgy by DuBose and Dorothy Heyward. The racial stew in the history and production of this work is just… American. (5th Avenue Theatre, 1308 Fifth Ave, 5thavenue.org, 8 pm, $40–$110, through June 29)