"It is a tale. Told by an idiot, full of sound and fury. Signifying nothing." 

Film critics love to quote Shakespeare when it comes to bashing the latest Michael Bay film, but in 1971 Roman Polanski turned Macbeth into exactly that. A tale of greed, ambition and its moral undoing, Polanski brought a strikingly different interpretation to the text. Here, Lady Macbeth (the beautiful Francesca Annis) is less calculating and more naive, while her husband (Jon Finch) is as much motivated by the bloody world around him as by the prophecies of the witches.

Blood. Grime. Mud. More blood. Polanski's Scotland revels in the dirty truth of it all: even the ghastly trio look like a gang of people you might find sleeping at a bus stop. At the time of its release, Lady Macbeth's naked soliloquy and the graphic nature of the violence were all attributed to the director's loss of his own wife, Sharon Tate, who was brutally killed by the Mansons a short while before. Well, that and the fact that it was funded by Playboy. But now, the vulnerabie exposure of Annis' young body and the butchering, stabbing and gouging only add to the horrible realism of it all.

Polanski hammers his vision of the familiar text home with his ending - a diversion from the text that sees Duncan's son Donalbain visit the witches just as Macbeth once did. The motivations on display aren't paranormal: they're normal, nasty and inevitably human. Polanski has turned Shakespeare's supernatural into a grubby, senseless reality. A world of sound of fury, signifying nothing. 

Polanski takes a similar approach in Rosemary's Baby. The story of Mia Farrow's wife and her ambitious husband (John Cassavetes) who find themselves expecting a baby that she believes to be the spawn of Satan is a genre classic - but the horror doesn't come from scenes of graphic demonic possession. Rather, it's the gradual breakdown of Rosemary, who goes from happy and pink to deathly pale in two incredibly freaky hours.

Is she imagining it all? Polanski's magical realism plays down the magical (compare that to a version by Guillermo del Toro, who would do the opposite) and leaves us rooted in the humdrum banality of everyday New York - where friendly neighbours and smiling doctors are as spooky as visions of Beelzebub having his way with you in your sleep.

That vision does happen, but unlike Macbeth, where dream sequences are a dazzling series of zooms into mirrors, Rosemary's hallucinations always involve tangible sets and physical props.

"This is no dream! This is really happening!" she cries out, as Christopher Komeda's descending clarinets loop over and over, dragging us back down to earth with a sickening bump. 

Place next your standard horror flicks and Polanski's matter-of-fact way of looking at the universe, where man's horrendous acts are as disturbing as the possibility of anything supernatural, is eerie, unexecpted and incredibly extra ordinary.  

Rosemary's Baby is on tonight at the BFI. For more information on the BFI Polanski season, visit the official site here - and remember to keep up with our Blogalongolanski series.