The song traditionally sung at midnight on New Year's Eve that begins “Should auld acquaintance be forgot” is “Auld Lang Syne.”
The lyrics are based on a Scots poem written by Robert Burns in 1788. The title means “old long since,” or more naturally, “for old times' sake.” Burns sent a version of the poem to the Scots Musical Museum, although the words developed from earlier Scottish folk material.
The song became strongly associated with New Year's celebrations through Scottish communities and emigrants. Its use spread internationally during the 19th and 20th centuries, especially in English-speaking countries. It is also sung at farewells, graduations, and memorial occasions, so it is not exclusively a New Year's song.
Many performances use a melody that differs slightly from regional versions. The familiar refrain asks whether old friendships should be forgotten, making it a natural song for marking a transition into a new year.