0:31 "Caught In The Lie" from the soundtrack of Little White Lie (a webseries by Team Starkid, the geniuses behind A Very Potter Musical)
9:55 "Goin' Back To Hogwarts" from A Very Potter Musical.
A Dalek saying exterminate is shortest at 0:02
Longest is a thirteen and a half minute clip of Eddie Izzard talking about Supermarkets
Granted neither of these are songs so...
Here Comes Science- They Might Be Giants (0:17)
Happy Ending/Over My Shoulder- Mika (10:21)
Shortest: Warrior Poets at :28. I don't know if that really counts as a song...it's the last few lines from the movie Braveheart.
Longest: Life is Beautiful by The Icarus Account, at 7:29.
I just wasted ten seconds of your life :10
Alices Resturaunt like 21 minutes