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
Ten Years After’s I’m Going Home at Woodstock is even more epic coming in at 11:24 on Youtube. Maybe the most epic of them all. Excellent sound quality. Headphones are recommended.

https://youtu.be/bW5M5xljdCI