This is the anthem of The Horde, Harry’s household. It was not written by him. Particularly skilled ethnomusicologists might like to compare the writing style of this and the works he did write, and consider whether his absence was evident.

It’s to the tune of Auld Lang Syne.

1980s or very early 1990s.

The Horde, The Horde, The Horde, The Horde.
The Horde, The Horde, The Horde!
The Horde, The Horde, the Horde, The Horde, The Horde
The Horde, The Horde, The Horde!