Elegant, thoughtful, persuasive – that is “Howards End, America,” Allen Shearer and Claudia Stevens’ new chamber opera, which just premiered in San Francisco’s Z space. Adapted from E.M.Forster’s outstanding novel, “Howards End,” set in 1910 Edwardian England, Shearer and Stevens turned fiction into music and lyrics set in 1950s America, a time of fierce race relations, class distinctions and challenging {…}