Mozart actually did use that melody in his Sonata for violin and Keyboard in G (Sonata #18) but he did not write it. This tune is much older than that. It could be as old as the 15th century, although there is no proof of that either. It just speculation...
It is 'Deck the Halls' The first line is, 'Deck the halls with boughs of holly.'
how to play Deck the halls Christmas song
Deck the Halls.
Deck the Halls - novel - was created in 2003.
Is deck the halls sacred or secular
Mozart
Rockin' Around the Christmas Tree
Holly
United States
deck the halls
Four Houses - 2012 Deck the Halls was released on: USA: 11 December 2012