Mario Bava is credited as the first director to breathe life into the giallo genre with his 1963 work, The Girl Who Knew Too Much. Ironically however, Bava is best known for being one of the most underrated auteurs of Italian horror. Often cited as the Italian Hitchcock, Mario Bava's beginnings as a painter and special effects assistant for his father were a small taste of what was to come. Early in his career, he worked with many of the pioneers of Italian horror including Riccardo Freda, before going solo and gaining popularity for his strong visual style. Though his filmography was plagued by a limited budget, Bava was resourceful and his style has been imitated by many, inspiring generations of filmmakers. His 1971 film Bay of Blood is considered one of the earliest slasher films and a direct influence on the original Friday the 13th.
The same year as Bava's giallo masterpiece, The Girl Who Knew Too Much, he released the horror anthology I Tre volti della paura otherwise known as Black Sabbath. The Italian title translates to The Three Faces of Fear, which is exactly what Bava delivers in three richly atmospheric Gothic tales. The film features horror icon Boris Karloff as the host, who also stars in the story, The Wurdalak. When American International Pictures distributed Black Sabbath in the U.S. they altered the film substantially. They rearranged the order of the stories which changed the climactic point and cut portions of episodes to make them more suitable for younger viewers. The film has since been restored to the original Italian version, which excludes Karloff's segments between stories but does contain his introduction and humorous epilogue. Sadly, they have dubbed his distinctive voice with that of an Italian actor. Also restored is Roberto Nicolosi's minimal ambient score which is a more effective contribution to the haunting storylines. Lastly, the AIP version indicates in the DVD liner notes that Bava's stories were adapted from the works of Chekhov, Tolstoy and Maupassant. It's more likely that the studio was following the same successful model used with Roger Corman and his Edgar Allan Poe adaptations and used the authors as a way to stir up interest.