The Scottish song associated with New Year's Eve that begins “Should auld acquaintance be forgot” is “Auld Lang Syne.”
The lyrics are based on a poem written by the Scottish poet Robert Burns in 1788. Burns sent the poem to the Scots Musical Museum and noted that parts of it came from older Scottish material. The title is Scots for “old long since,” or more naturally, “for old times’ sake.”
The song became strongly linked with New Year's celebrations through performances and printed songbooks, especially in English-speaking countries. People commonly sing it while holding hands in a circle, although customs differ from place to place. The melody now familiar internationally was paired with the lyrics in later musical arrangements.
“Auld Lang Syne” is not exclusively a New Year's song. It is also used at farewells, memorials, graduations, and other moments of transition. Another frequent misunderstanding is that Burns composed every element from scratch; the poem reflects older traditional verses and expressions.