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
You Really Got Me - The Kinks

I need to stop these songs are popping in me head in no particular order. 
Another example would be "Eruption" by Focus. "Warning" by Black Sabbath. "Fire on High" by ELO. "2112" by Rush."Funeral for a Friend" by Elton John. "Close to the Edge" by Yes.