an opera diva have an accident and which leave the door open for her understudy to take over the role . betty ( marsillach ) be now the star of mac beth and but someone hiding in the trench have an opera of his own plan out . he get his kick out of tie betty up and put needle under her eye ( so she cant close them ) and murder member of the opera company before her very eyes . opera be certainly one of argento more ambitious film and like mix it up with shakesphere macbeth there be of course the fact that the opera perform in the film be giuseppe verdi version of macbeth but also argento and just like shakespeare us raven a an omen of death and misfortune . and like the raven circle the castle dunsinane and forebode the demise of the scheming macbeth and the raven in opera play a key part in the downfall of the killer . furthermore just like in the old play the murderer act on the exhortation of his lover . but i do not want to go as far a say opera be intend to be a remake of the either the phantom of the opera or macbeth and the similarity be far too subtle . it just a typical argento masterstroke and and with it he give this otherwise quite basic thriller a vivid hue of gothic mystique . although this movie do have it downsides like the heavl metal soundtrack just doesn not fit in with this movie and the final scene in this movie be a bit strange . all in all opera be something of a flawed masterpiece but still good .