《魂斷藍橋》的主題曲原版是蘇格蘭民歌《友誼地久天長》。

“友誼地久天長”，即蘇格蘭蓋爾語“Auld Lang Syne”，這本是一首非常有名的詩歌，直譯為逝去已久的日子。

這首詩後來被譜了樂曲，除了原文蓋爾語版本外，這首歌還被許多國家譜上了當地語言，絕對是一首膾炙人口的世界經典名曲。

《友誼地久天長》歌曲的原版歌詞如下：

Auld Lang Syne

ChorusFor auld lang syne

my dear

For auld lang syne

We"ll tak a cup o"kindness yet

For auld lang syne

Should auld acquaintance be forgot

And never brought to mind

Should auld acquaintance be forgot

And auld lang syne

And surely ye"ll be your pint-stowp

And surely I"ll be mine

And we"ll take a cup o" kindness yet

For auld lang syne

We twa hae run about the braes

And pou"d the gowans fine

But we"ve wander"d monie a weary fit

Sin" auld lang syne

We twa hae paidl"d in the burn

Frae mornin" sun till dine

But seas between us braid hae roar"d

Sin" auld lang syne

And there"s a hand

my trusty fiere

And gie"s a hand o" thine

And we"ll take a right guid-willie waught

For auld lang syne