Four Flies on Grey Velvet (1972)

A musician is stalked by an unknown homicidal maniac, who blackmails him for the accidental killing of another stalker.

Director: Dario Argento

Cast: Michael Brandon, Mimsy Farmer, Jean-Pierre Marielle, Aldo Bufi Landi, Calisto Calisti, Marisa Fabbri, Oreste Lionello, Fabrizio Moroni, Corrado Olmi, Stefano Satta Flores, Laura Troschel, Francine Racette, Bud Spencer, Dante Cleri, Guerrino Crivello, Gildo Di Marco, Tom Felleghy, Leopoldo Migliori