Ok I lied my longest one is "A Thousand Suns" by Linkin Park. "But zorrodude, that's an album not a song!" It actually is one song, they have the "full version" song which plays the whole album, which by the way is all continuous. It runs 47:57.
Shortest song is at 4 seconds. "Overheard in a Wawa Parking Lot" by Bloodhound Gang. Although there aren't really any instruments in that one.
[Edited by zorrodude, 1/4/2011 10:03:23 PM]
I too have that album...and I would say that is cheating.