"If You Go Away" is Rod McKuen's English-language version of the 1959 Jacques Brel song "Ne me quitte pas".
[1] The complex melody is partly derivative of classical music: the "But if you stay..." passage comes from Franz Liszt's Hungarian Rhapsody No.
The English version omits a section of the original version in which the singer begs his lover to give their relationship a second chance, using examples derived from the natural world: "I will tell you of those lovers who saw their hearts catch fire twice;" "Fire has often been seen gushing out of an ancient volcano we thought too old"; "There are, people say, burnt lands that produce more wheat than the best of Aprils".
Nick Currie, better known as Momus, returned to Brel's original song and translated it as "Don't Leave" in 1986, released initially on the Jacques EP and then on an expanded reissue of the album Circus Maximus.
This was lyrically closer to the original, notably using the formulation "Me, I'll ..." (common as "moi, je ..." in French but rarely used in English).