Just discovered: a Swedish documentary about Birgit Nilsson, featuring footage of the diva at the Met getting ready to sing Tosca opposite Gianni Raimondi (replacing Franco Corelli who was apparently ill), giving a party for fans in her modest sublet, giggling, preparing for a recital tour, rehearsing Tristan und Isolde and generally doing interesting things.  (Narration is in Swedish, but in the New York sequences, Nilsson and others mostly speak English.)