At the stroke of midnight this New Year's eve, millions of people around the world will sing that old favourite "Auld Lang Syne" but how many of us will actually know what it means?

The Scottish poem and familiar tune is considered to vie for the title of most extensively known song on the planet after "Happy Birthday".

An exhibition in New York makes known that the odd sounding words are simply the tip of a gloomy and tender iceberg. "This is a song we all sort of know. But we don't know what it means, or where it comes from," said Christine Nelson, curator of the exhibit at the Morgan Library & Museum in Manhattan.

The frequent supposition is that Scottish poet Robert Burns composed the ballad. The reality seems less uncomplicated. The first recorded reference comes from Burns, who in 1788 wrote to a female friend about his latest reunion with a long-lost acquaintance.

Remarking on the theme of long-standing friendship, Burns mentions something about it in his letter.

"The Scots phrase, 'Auld lang syne,'" which translates as "old time's sake," He wrote. Right there, the start of the nostalgic song seem to have been planted. On the other hand, 5 long years have already passed before Burns actually wrote the word down and sent them to a publisher-even then it seems almost like an addendum.

It would be an additional 2 centuries before that compelling blend of reminiscence and an occasion for a noisy sing-along was made into a worldwide phenomenon. The song was popularized in the 1920s and '30s by American big band leader Guy Lombardo, then again in a string of Hollywood movies (most significantly in the 40's movie, "It's A Wonderful Life") and the rest, as they say, is history.