The Vampire of the Opera (aka Il Mostro Dell'Opera)

An acting troupe secures an old theater for the group's new play. They are warned by the aging caretaker that the theater is home to a vampire, who might be awakened. The group pays no heed, though, and when the vampire shows up, it sees that the most beautiful member of the troupe looks lke the woman he once loved in real life. Things spiral downhill from there. Lots of gothic thrills in this well-made chiller.