Bill D wrote: "World's Longest Song...."

Of course, there are many World's Longest Songs. For example, there is "Yon Yonson" (which I think we can safely declare "The World's Longest Scandihoovian Song"):

My name is Yon Yonson,
I come from Visconsin,
I work in the lumber mills there,
Ven I valk down the street,
Qll the people I meet, say,
"Hello, vot's your name?" and I say
My name is Yon Yonson....

Or, "You Remind Me of a Man":
"You remind me of a man."
"What man?"
"The man with the power."
"What power?"
"The power of Hoodoo."
"Who do?
"You do."
"Do what?"
"You remind me of...."

Maggie Kerr Peirce had one,
'Twas a dark and stormy night,
And the rain came down in torrents.
The Bugler's Band sat round the fire,
And the captain said to Iona,
"Iona, tell us a tale...." (and the tale began)
'Twas a dark and stormy night...."

One could even include "Where Have All the Flowers Gone" here, although that's intended to be a closed loop, not an infinite loop.

J. R. R. Tolkien's "Errantry" was set to music, so I suppose we could throw it in, too.