Deck the Halls is a traditional Christmas Carol. The music of Deck The Halls is actually a Welsh winter carol called Nos Galan. The tune is also known in its singular: Deck The Hall, even thought the first line of lyrics says otherwise:

Deck the halls with boughs of holly,
Fa la la la la, la la la la.
Tis the season to be jolly,
Fa la la la la, la la la la.
Don we now our gay apparel,
Fa la la, la la la, la la la.
Trollthe ancient Yule tide carol,
Fa la la la la, la la la la.

The repetitive nature of the lyrics has made it easy for people to change them in very satirical ways. Our Deck The Halls sheet music refrains from such behavior.