The Man and the Monster  (1958)

Theatrical Release Information:
The Man and the Monster

The Mexican horrorama Man and the Monster is yet another wrinkle on the Faust story. A concert pianist, desirous of international fame, sells his soul to the devil. Satan's price: whenever the pianist plays a particular selection, he turns into a monster. After a string of brutal murders perpetrated by this musical Jekyll/Hyde, he is foiled by a quickwitted concert master. When the orchestra strikes up the fatal tune, the pianist goes through his slavering metamorphosis before a packed audience, who presumably spend the rest of the evening paging through their programs to see if the monster is a hitherto unannounced guest artist. Abel Salazer produced, wrote and starred in Man and the Monster, which was originally titled El Hombre Y El Monstruo. ~ Hal Erickson, All Movie Guide