The Disintegration Loops certainly counts as a set as it was officially released as a 9LP+5CD+DVD box set. Frown is quite right as it clocks in at 5:53:36 for either the CD or LP version.
Skimming through my collection I see a few other long albums or sets of note. Here they are in order of ascending length:
- Robert Rich's Somnium Sleep Concert (7:00:01)
- Robert Rich's follow-up - The Somnium Continuum (8:00:01)
- The CBS Radio Mystery Theater - The New Adventures of Sherlock Holmes (15:50:44)
- Plastikman - Arkives (32:37:46)
- The History of Electroacoustic Music Collection (55:19:22)
- The Adventures of Sherlock Holmes BBC Radio Dramas (58:09:45)
- The Complete Sherlock Holmes Audiobook (62:21:36)
- Klaus Schulze - The Ultimate Collection (64:50:32)
- The Franklin Mint's 100 Greatest Recordings of All Time (77:19:49)
- Beethoven Bicentennial Collection - 80 LP (100:37:50)
- 111 Years of Deutsche Grammophon: The Collector's Edition (116:41:48)
- The World's Greatest Jazz Collection 500CD Box Set (533:53:43) - that's over 22 days of jazz.
Unfortunately, I suggest steering clear of the last item on the list. Licensing prevented the label from including most of what listeners would call "Worlds-Greatest Recordings", and the set is the resulting cutting room floor scraps.
But the other items on the list are excellent stuff.