"I Have But One Heart"
is a popular song
The music was written by Johnny Farrow, the lyrics by Marty Symes. The song was published in 1945.
The song was also sung by the character Johnny Fontane played by Al Martino in the movie The Godfather, during Connie's wedding, and was on the soundtrack of the movie.
The song is adapted from the traditional Italian song "O Marenariello."