Murder-Rock: Dancing Death (movie, 1984)

The world of dance can be brutal. The rehearsals are grueling. The competition is fierce. At the Arts for Living Centre in New York City, the best of the best are dying for a part in a major production. But only a select few will be chosen. The selection process seems to be at the hands of mysterious killer who pierces women's bare breasts with a hatpin, puncturing their hearts. Ambition and jealousy appear to be the motive, which makes everybody a suspect!