Gertrude Stein has rarely been anyone's idea of light entertainment. But as directed by David Herskovits, this short by her from 1921, seldom seen outside of academia, has an exhilarating air of discovery. This Target Margin production, which opened in January at the Bushwick Starr, finds the fun - and the sense - in Stein's seeming nonsense, as pedestrian words seem to sprout wings and fly (:50).