El hombre y el monstruo (1959)

When the snoopy reporter of a music magazine Ricardo Souto travels from Mexico City to the countryside to pay a visit to the former pianist and conductor Samuel Magno, he finds that he lives secluded in a house with his mother Cornelia and his protegee Laura. Ricardo briefly interviews Samuel and learns that he is preparing Laura to be introduced in a Tchaikovsky concert where he will be the conductor very soon. What Ricardo does not know is that the envious Samuel has made a pact with the devil to be the best pianist of the world, and he killed the number one, Alejandra. However, the devil has played a prank on Samuel and, when he plays piano, he becomes a monster. Now Samuel wants to prepare Laura to become the best pianist and break the curse.