World's Longest Song, Opera, Poem or Muscial.

I have written posts on the World's longest Books and Movies.
But what about the longest song, operas, musical or poem.

According to numerous sources, Apparente Libertà by Giancarlo Ferrari is the longest song in the world.
It lasts around 76 minutes.

Surely that length of time could be bettered? How about a song the lasts centuries made by computer?
An artificial intelligence computer could be programmed to write a coherent and well performed song, musical, opera or poem that lasts centuries, or even longer such as millenia. It could be made by a highly advanced supercomputer, that is so powerful it make the performance of a poem, song, musical or opera last for centuries. Once again the work of art could be made by a cult, family or artistic group. The cult, group or family could spend entire generations of lives listening to or watching the performance.
Maybe the song could be in the background as some spaceship sales over thousands of years to another planet.

The song would then be reviewed by the cult, family or artistic group.
 Longest Opera -
The longest performed opera tends to be Die Meistersinger von Nürnberg by the German Wagner. It can last over 5 hours, when cut. Which is not that long.
Longest Poem -
The Mahābhārata.
A poem that is around 1.8 million words. The Mahābhārata is the longest poem in the Planet Earth.