Ever wonder why we sing “Auld Lang Syne” at midnight on New Year's Eve? 

“Auld Lang Syne,” which is public domain, is a poem that was written and combined with a traditional folk song by Robert Burns in 1788. It means 'to bid farewell,' or saying goodbye to the old year. The song is also popular at graduations and funerals as a way of ending something.

Some say the tradition started with Guy Lombardo and the Royal Canadian Band. Today I Found Out says the band has sold over 300 million records to date. "Guy Lombardo himself has three stars on the Hollywood Walk of Fame, and he was once the “Dick Clark” of New Years before Clark and his “New Year’s Rockin’ Eve,” attempting to appeal to younger audiences, started supplanting “Mr. New Year’s Eve,” Guy Lombardo."

In 1929 on New Years Eve Guy Lombardo and his band played at the Roosevelt Hotel in New York City.  The show was on the radio before midnight Eastern-time on CBS, then after on NBC radio. Midnight struck between the two shows and the song the band was playing Auld Lang Syne

[Information from Today I Found Out and  Wikipedia.]