The song traditionally sung at New Year's celebrations, based on a poem by Robert Burns, is “Auld Lang Syne.”
The Scottish poet Robert Burns sent a version of the poem to the Scots Musical Museum in 1788. The phrase means “old long since” and is commonly understood as referring to times gone by or old friendships. Burns drew on older Scottish words and folk material rather than inventing every line from scratch.
The familiar melody became strongly associated with New Year's Eve during the 19th and 20th centuries. It is now performed in many countries, often immediately after midnight, although its lyrics are not specifically about New Year's Day. The song also appears at farewells, reunions, graduations, and memorial occasions.
Pronunciation and wording vary internationally. “Auld Lang Syne” is Scottish rather than standard modern English, which explains why some listeners recognize the tune without understanding the title.