Led Zeppelin — Dyer Maker (crd)

Basically, it follows the pattern C Am F G (all E-form bar chords):
 
 C     Am     F  G
 Oh oh oh oh oh, you don`t have to go, ...
 
 repeated endless number of times, until:
 
 Am                         G
 When I read the letter you wrote me, ...
 
 which also repeats a few times before going back to the verse.