Opera aka Terror at the Opera (1987) 

A young opera singer (Betty) gets her big chance when the previous star of a production of Verdi's Macbeth is run over by a car. Convinced the opera is bad luck she accepts, and becomes the target (in Argento's unmistakable style) of a psychopath - a man she has been dreaming of since childhood. - IMDb


Watch the Full Movie (Divx)

Source 2