Longest continuous playing songs


I like (and looking for) continuous playing music, it could be one song or a group of songs that play uninterrupted, the longer, the better. Does anybody have any suggestions?

Thanks for any suggestions,

Steve
sc2
Pink Floyd-

Atom Heart Mother from Atom Heart Mother- 23:44

Echoes from Meddle- 23:29

Shine On You Crazy Diamond (Parts I-V) from Wish You Were Here- 13:31

Shine On You Crazy Diamond (Parts VI-IX) from WYWH- 12:28

Dogs from Animals- 17:06

John
I was driving over to Santa Monica for sushi tonight. About a 30 minute drive. Some college station fron Cal State Northridge was playing Grateful Dead live from Winterland in Nov. 1973. The tune lasted the entire drive.
Many good suggestions, one not hit yet is the Beastie Boys Paul's Boutique, it is one continuos groove, and like Pink Floyds Meddle, starts where it ends so it could play on forever.

Rush 2112 is pretty long as wel.
Mike Oldfield is famous for long running songs. My favorite is "Ommadawn" which runs for 36+ minutes. Tubular Bells runs 48 minutes.