69 love songs for sure counts for me (there’s also “50 song memoir” which isnt quite as long but is still pretty long.) I never bothered listening to Emancipation in full, prince has too much other stuff I’d rather listen to instead.

yeah i guess if you count novelty stuff i have heard the lips 6 hour song. its got some cool stretches of jamming but isnt all that great.
The Flaming Lips 24 hour song on the other hand is great but I have not listened to the whole thing obviously. but the album-length edited version “7 Skies H3” is among their best post-Embryonic works.

Also long ambient stuff counts i guess. Disintegration loops is like 4 hours or something. Everywhere at The End Of Time is 6 and a half hours. Probably wont force myself to sit through the latter ever again, but I could see myself giving the loops another full go through one of these days.