El Hombre y El Monstruo: 1958
Cinematographa Absa
Black and White
aka The Man and the Monster

Director: Rafeal Baledon
Cast: Enrique Rabal, Abel Salazar

Plot: A concert pianist turns into a werewolf whenever he plays. Only his mother's touch can help him. I'd love to see how it was written in to have him play more than once.