What is the epic song of a group?

Here are some elements that I plucked of the internet to help convey the intent of my post. Don't get me wrong some of the songs members brought up are awesome and powerful.
"Epic Rock is an alternative label for Symphonic Metal and similarly grand-sounding Rock Music for North America and elsewhere that Metal is defined by a complete absence of pop elements. ... Music that sounds "epic" in addition to being Rock."   

"majestic;impressively great:the epic event"

"Oftentimes the climax at the moment where most people go "whoa...this is epic..." has an adjusted meter of some kind. Sometimes the music will go into a doubletime feel; in my opinion, this matches the human reaction of relaxation at a moment of climax. (Insert sex analogy"

My choice for another epic song would be Baba O'Reilly (aka Teenage Wasteland) by the Who. Builds slow and builds and builds till a feverish ending. Great lyrics. Epic

Ahhh here is another one. Yes "Close to the Edge" Elements of different intensties and moods. I hear several epic parts of this masterpiece. The organ and guitar solo near the middle and Jon Anderson's emotional ending. "Epic"

Iron Butterfly: In-A-Gadda-Da-Vida
Steely Dan: Hey Nineteen
Wishbone Ash: Throw Down the Sword
Yes: Starship Trooper
Allman Brothers: Whipping Post
Janis Joplin/Big Brother: Summertime

King Crimson - Court of the Crimson King AND Starless.
Yes - Close to the Edge.
Rush - 2112.
Pink Floyd - Us and Them.
Van Der Graaf Generator - A Plague of the Lighthouse Keepers.
Can - Halleluhwah.
WAR - The World is a Ghetto.
Genesis - Suppers Ready.
Lynyrd Skynyrd - Free Bird.
Mike Oldfield - Tubular Bells.
Roxy Music - Avalon.
Henry Cow - Living in the Heart of the Beast.
Zappa - Way too many to list.....