What is the epic song of a group?


I will start. I vote for Stairway to Heaven for Zep. Its grand with a great finish. I will throw in Salisbury by Uriah Heap. Ok lets see some posts of what you think is a groups masterpiece.
128x128blueranger
Some more goodies for you....
Sara - Bob Dylan
Lightnin strikes - Lou Christie
Cheryl's goin home - Bob Lind
On Saturday afternoons in 1963 - Rickie Lee Jones
Monday Monday - Mamas and Papas
Thats Right - Neil Christian
Elouise - Barry Ryan
Stuck inside of mobile with the memphis blues again - Bob Dylan
djones51 -
Appreciate the explanation for your choice of Tomorrow Never Knows as The Beatles’ epic. Revolver and that track in particular certainly announced a "new direction" they were taking
It isn't their best or most memorable song maybe 'epic' isn't the right catagory perhaps song that redefined a group or introduced something new. The wiki page on the song  is an interesting read. 
OK what about The Rolling Stones and Goin' home from Aftermath UK version of course