O Christmas Tree

The tune goes back much further than Christmas trees themselves--it's based on a folk melody with roots in 16th-century Germany. A teacher named Ernst Anschütz added the verses we know today in 1824, but even his words aren't really about a decorated Christmas tree; they're about the fir tree's evergreen branches as a symbol of loyalty and constancy, since it stays green all year round. The custom of decorating trees for Christmas only really caught on afterward, and the song came along for the ride, eventually becoming one of the most recognizable carols in the world.