It’s no longer summertime, but tonight it’s time for “Summertime.” The PBS Fall Arts Festival presents the San Francisco Opera’s rendition of The Gershwins’ Porgy and Bess, starring Eric Owens as Porgy and Laquita Mitchell as Bess. The musical with an all-black cast, based on the play by DuBose and Dorothy Heyward and with music and lyrics by George and Ira Gershwin, opened on Broadway in 1935 – and was performed there, most recently, in a Tony-winning 2012 revival starring Norm Lewis and Audra McDonald. Now we get to see how the West Coast performs it, in a TV production that can be considered very Off-Off-Broadway. Check local listings.