Langston Hughes' Black Nativity is a "gospel song play," which means a brief play about the birth of Christ with a whole lot of gospel songs. It ranks with The Hard Nut as an irreverent, joyful tonic to holiday treacle like The Nutcracker, and San Francisco has had its own annual production ever since ... well, since last year, when the Lorraine Hansberry Theater mounted one. The Nativity doesn't have a permanent musical score; theaters pay for the rights to Hughes' script but come up with the music separately. This version owes much of its power to singer, arranger, and songwriter Arvis Strickling Jones, who composed or arranged many of the songs. She serves as minister of music at St. Stephen Baptist Church in San Francisco; she's been nominated for three Grammys, and her ecstatic and tender version of "Sweet Little Jesus Boy" last year was worth the price of admission. This year, dancers from Ronnie Reddick's City Slam group will complement Jones and her gospel chorus. The songs range in style from straight gospel and blues to rap. "We build our temples for tomorrow," said Hughes, who wrote Black Nativity for a performance in church in 1961, "as strong as we know how."