“A child bounces a ball; a family sits down for a meal; a parcel is delivered; a woman tries on her wedding dress … welcome to Herbert Wernicke’s vision of Bach as kitchen-sink drama.” In his music-theatre program “Actus Tragicus” (now being revived in Edinburgh), the late director presents a giant doll’s house in which “both chorus members and soloists go about their lovingly detailed, humdrum existence” as they perform half a dozen Bach cantatas.