Famed mezzo-soprano Frederica von Stade sings in this weekend’s Bay Area performances of Street Requiem, a choral contata to call attention to the plight of people living on our streets and in other insecure conditions around the globe. On this week's Out in the Bay ( 7pm Thursday ), Australian co-creators Andy Payne and Kathleen McGuire – conductor and artistic director of the San Francisco Gay Men’s Chorus from 2000 to 2010 – play selections from Street Requiem’s World Premiere in Melbourne