O Christmas Tree is a Christmas song based on the German O Tannenbaum.
“Anschutz based his text on a 16th-century Silesian folk song by Melchior Franck, “Ach Tannenbaum”. Joachim August Zarnack (de) (1777–1827) in 1819 wrote a tragic love song inspired by this folk song, taking the evergreen, “faithful” fir tree as contrasting with a faithless lover. The folk song first became associated with Christmas with Anschütz, who added two verses of his own to the first, traditional verse. The custom of the Christmas tree developed in the course of the 19th century and the song came to be seen as a Christmas carol.”
A Tannenbaum is a fir tree and the lyrics refer to the fir’s evergreen qualities as symbols of constancy and faithfulness. No reference to Christmas or a Christmas tree is ever made.
Anschütz’s version still had treu (true, faithful) as the adjective describing the fir’s leaves (needles), harking back to the contrast to the faithless maiden of the folk song. This was changed to grün (green) at some point in the 20th century after the song had come to be associated with Christmas.
The song has become a classic Christmas carol and recorded by numerous artists.