The longest recorded song is over 69 hours long - Apparently.
The "Longplayer" composition, a musical piece by Jem Finer, has been playing non-stop since January 1, 2000. The song is designed to last for 639 years, with the music adapting and changing over time to reflect the changing environment and external influences. The project is a collaboration between the composer and the Longplayer Trust, a UK-based charity, and is intended to be a continuously evolving work of art. The song's length is based on a mathematical formula that ensures it will eventually run its course on January 1, 2639.